1 00:00:07,639 --> 00:00:05,570 hello everyone and welcome to this 2 00:00:09,709 --> 00:00:07,649 week's Hubbell hangout my name is Tony 3 00:00:11,240 --> 00:00:09,719 Darnell and we've got another great 4 00:00:13,039 --> 00:00:11,250 hangout planned for you this week 5 00:00:15,980 --> 00:00:13,049 astronomers using the Hubble Space 6 00:00:17,689 --> 00:00:15,990 Telescope have been looking at the Large 7 00:00:20,420 --> 00:00:17,699 Magellanic Cloud and in particular the 8 00:00:23,300 --> 00:00:20,430 tarantula nebula and they have found a 9 00:00:25,099 --> 00:00:23,310 great many wonderfully large luminous 10 00:00:28,429 --> 00:00:25,109 stars that they're gonna be telling us 11 00:00:30,859 --> 00:00:28,439 about and this I don't know this one's 12 00:00:32,720 --> 00:00:30,869 this one's great we all love big things 13 00:00:34,250 --> 00:00:32,730 right well we talked about the largest 14 00:00:36,680 --> 00:00:34,260 galaxies the most massive galaxies the 15 00:00:37,880 --> 00:00:36,690 most biggest the biggest plan of the 16 00:00:40,160 --> 00:00:37,890 largest planet the most massive planet 17 00:00:42,799 --> 00:00:40,170 well here if you've ever been wondering 18 00:00:44,389 --> 00:00:42,809 about the most massive star in known in 19 00:00:45,440 --> 00:00:44,399 the universe then you're gonna want to 20 00:00:47,240 --> 00:00:45,450 stick around because we're going to talk 21 00:00:49,150 --> 00:00:47,250 a lot about that it's in these 22 00:00:52,250 --> 00:00:49,160 observations and so we're gonna 23 00:00:54,560 --> 00:00:52,260 introduce you to the most one of the 24 00:00:56,119 --> 00:00:54,570 most no it is the most massive star in 25 00:00:57,889 --> 00:00:56,129 the universe's the current record holder 26 00:01:00,560 --> 00:00:57,899 so we're gonna talk about that this week 27 00:01:03,170 --> 00:01:00,570 and a bunch of other things but before I 28 00:01:04,759 --> 00:01:03,180 introduce my guest let me oh and I 29 00:01:06,140 --> 00:01:04,769 should point out that dr. Carol 30 00:01:09,080 --> 00:01:06,150 Christian could not join us this week 31 00:01:10,880 --> 00:01:09,090 she is in gay Paree we're at a 32 00:01:14,120 --> 00:01:10,890 conference and of course as with all 33 00:01:16,670 --> 00:01:14,130 conferences Internet bandwidth is an 34 00:01:18,469 --> 00:01:16,680 issue so she is unable to join us this 35 00:01:20,480 --> 00:01:18,479 week but she'll be back next week to 36 00:01:22,190 --> 00:01:20,490 tell us hopefully what she did in Paris 37 00:01:25,789 --> 00:01:22,200 because it's an interesting place to 38 00:01:28,580 --> 00:01:25,799 visit so will with no more ado no 39 00:01:31,700 --> 00:01:28,590 further ado I'd like to introduce my 40 00:01:32,510 --> 00:01:31,710 colleague Scott Lewis hi Scott how you 41 00:01:33,920 --> 00:01:32,520 doing Tony 42 00:01:37,370 --> 00:01:33,930 good to see you again I'm glad you're 43 00:01:39,380 --> 00:01:37,380 back I just why I was here in spirit 44 00:01:42,620 --> 00:01:39,390 please you just sit there and wait until 45 00:01:45,200 --> 00:01:42,630 you I actually live in the Internet I 46 00:01:46,850 --> 00:01:45,210 just oh you know I've actually no longer 47 00:01:49,370 --> 00:01:46,860 of a physical body I just live in the 48 00:01:52,310 --> 00:01:49,380 internet it saves on rent quite a bit I 49 00:01:54,170 --> 00:01:52,320 suppose so I did so do you so you just 50 00:01:55,819 --> 00:01:54,180 sit there until from Hubble hanging out 51 00:01:57,260 --> 00:01:55,829 to Hubble hang out then I just say here 52 00:02:00,139 --> 00:01:57,270 I tweet every once in a while watch a 53 00:02:01,910 --> 00:02:00,149 lot of Netflix do you lot a Netflix on 54 00:02:03,260 --> 00:02:01,920 the internet yeah that's what I'm 55 00:02:04,850 --> 00:02:03,270 hearing it takes up a lot of space on 56 00:02:06,560 --> 00:02:04,860 the Internet these days well welcome 57 00:02:08,240 --> 00:02:06,570 back and it's good that you'll be the 58 00:02:10,100 --> 00:02:08,250 one you'll be the one that will be 59 00:02:12,680 --> 00:02:10,110 driving the internet for us which brings 60 00:02:13,420 --> 00:02:12,690 me to your questions and comments this 61 00:02:15,429 --> 00:02:13,430 is an inner 62 00:02:18,580 --> 00:02:15,439 - medium folks this is a hangout not 63 00:02:20,110 --> 00:02:18,590 only do Scott and I hang out and talk 64 00:02:22,059 --> 00:02:20,120 about science but we also do it with 65 00:02:23,170 --> 00:02:22,069 astronomers and astrophysicists all over 66 00:02:26,440 --> 00:02:23,180 the world who use the Hubble Space 67 00:02:28,660 --> 00:02:26,450 Telescope now is your chance if you want 68 00:02:30,369 --> 00:02:28,670 to ask them questions and can't leave 69 00:02:32,110 --> 00:02:30,379 comments and we hope you will do that 70 00:02:34,330 --> 00:02:32,120 and Scott's gonna tell you the best way 71 00:02:36,009 --> 00:02:34,340 to do it well that's guys absolutely so 72 00:02:37,809 --> 00:02:36,019 the the best and easiest way for us 73 00:02:39,520 --> 00:02:37,819 while we're live is actually I'm already 74 00:02:41,649 --> 00:02:39,530 seeing a bunch of other people in here 75 00:02:43,569 --> 00:02:41,659 we are using the YouTube live chat since 76 00:02:44,949 --> 00:02:43,579 this is a YouTube live event so there's 77 00:02:47,379 --> 00:02:44,959 a bunch of people so hello everyone 78 00:02:51,940 --> 00:02:47,389 and yes I am being snarky Astro girl won 79 00:02:55,869 --> 00:02:51,950 USA oh yes hello esfir girl so yes 80 00:02:57,280 --> 00:02:55,879 please continue to comment I put links 81 00:02:59,559 --> 00:02:57,290 into the press releases into the 82 00:03:01,899 --> 00:02:59,569 different files that we'll be sharing 83 00:03:03,280 --> 00:03:01,909 drink today so if you have any questions 84 00:03:04,809 --> 00:03:03,290 or comments on those or anything that 85 00:03:07,720 --> 00:03:04,819 we're discussing please let us know 86 00:03:09,490 --> 00:03:07,730 they're in live chat and as Tony said as 87 00:03:11,770 --> 00:03:09,500 well we are over on Twitter so I'm live 88 00:03:13,869 --> 00:03:11,780 tweeting this event using the hashtag 89 00:03:15,640 --> 00:03:13,879 Hubbell hangout and so if you're 90 00:03:17,409 --> 00:03:15,650 watching this after the fact you can 91 00:03:19,830 --> 00:03:17,419 leave comments on YouTube or continue 92 00:03:22,659 --> 00:03:19,840 the conversation on Twitter and we will 93 00:03:24,909 --> 00:03:22,669 be continuing that on I'll be tweeting 94 00:03:28,390 --> 00:03:24,919 as both myself and as Hubble telescope 95 00:03:30,280 --> 00:03:28,400 and we'll be really trying to focus on 96 00:03:32,559 --> 00:03:30,290 your questions and comments and and give 97 00:03:35,800 --> 00:03:32,569 you more insight into these supermassive 98 00:03:38,080 --> 00:03:35,810 stars in the trench of nebulae awesome 99 00:03:39,280 --> 00:03:38,090 okay so as I said at the top of this 100 00:03:41,589 --> 00:03:39,290 hangout we've got a really great one 101 00:03:43,360 --> 00:03:41,599 planned for you an international team of 102 00:03:45,099 --> 00:03:43,370 astronomers using the ultraviolet 103 00:03:47,949 --> 00:03:45,109 capabilities of NASA's Hubble Space 104 00:03:51,309 --> 00:03:47,959 Telescope has identified nine monster 105 00:03:54,430 --> 00:03:51,319 stars with masses over 100 times the 106 00:03:56,280 --> 00:03:54,440 mass of the Sun 100 times the mass of 107 00:03:59,319 --> 00:03:56,290 the Sun and the star cluster known as 108 00:04:02,259 --> 00:03:59,329 r136 this makes for the largest sample 109 00:04:03,879 --> 00:04:02,269 of very massive stars identified to date 110 00:04:06,009 --> 00:04:03,889 and so three of the members of that 111 00:04:08,500 --> 00:04:06,019 international team are with us now I 112 00:04:11,110 --> 00:04:08,510 have dr. Fabian Schneider he is from the 113 00:04:12,969 --> 00:04:11,120 University of Oxford as and he's an 114 00:04:15,369 --> 00:04:12,979 astrophysicist they're also joining me 115 00:04:17,890 --> 00:04:15,379 is Professor Paul Crowther he's from the 116 00:04:19,750 --> 00:04:17,900 University of Sheffield and Selma 117 00:04:21,459 --> 00:04:19,760 Dominque from the University of 118 00:04:23,709 --> 00:04:21,469 Amsterdam she's and astrophysicists 119 00:04:26,400 --> 00:04:23,719 there welcome folks but good to have you 120 00:04:29,409 --> 00:04:26,410 on our hangout I think 121 00:04:32,020 --> 00:04:29,419 okay so let's get to this so let's see I 122 00:04:34,510 --> 00:04:32,030 think I'll start with with you Fabian 123 00:04:37,510 --> 00:04:34,520 let's see the give us an ID why don't 124 00:04:41,830 --> 00:04:37,520 you start with what the observations 125 00:04:45,969 --> 00:04:41,840 were what was your purpose and looking 126 00:04:48,640 --> 00:04:45,979 at this particular star cluster well as 127 00:04:49,960 --> 00:04:48,650 you know it's far away it's a star 128 00:04:52,450 --> 00:04:49,970 cluster in the Large Magellanic Clouds 129 00:04:56,020 --> 00:04:52,460 it's let's talk about that the Large 130 00:04:58,390 --> 00:04:56,030 Magellanic Cloud is what it's enabling 131 00:05:02,170 --> 00:04:58,400 dwarf galaxies next to our Milky Way one 132 00:05:03,939 --> 00:05:02,180 of our next closest companion so to say 133 00:05:06,399 --> 00:05:03,949 so it's sort of one of those satellite 134 00:05:08,589 --> 00:05:06,409 galaxies around lutely exactly oh yeah 135 00:05:10,749 --> 00:05:08,599 but within that there's a huge star 136 00:05:12,309 --> 00:05:10,759 forming region a gigantic one probably 137 00:05:14,610 --> 00:05:12,319 the largest in the local universe at 138 00:05:18,100 --> 00:05:14,620 least largest that we can really 139 00:05:19,870 --> 00:05:18,110 dissolve into individual stars and in 140 00:05:22,059 --> 00:05:19,880 that huge star forming region which by 141 00:05:24,969 --> 00:05:22,069 the way was supposed to be a single star 142 00:05:27,219 --> 00:05:24,979 in the past hence the name $30 right so 143 00:05:29,709 --> 00:05:27,229 dourados had just a consolation in the 144 00:05:32,140 --> 00:05:29,719 south and it was a circuit thirties 145 00:05:33,879 --> 00:05:32,150 brightest in there and in that region 146 00:05:37,570 --> 00:05:33,889 you have a huge star forming crowd and 147 00:05:39,100 --> 00:05:37,580 in there another huge star cluster so 148 00:05:41,409 --> 00:05:39,110 it's really far away and the cluster 149 00:05:43,749 --> 00:05:41,419 itself is tiny so if you want to be 150 00:05:46,120 --> 00:05:43,759 solve it you're gonna go and look for 151 00:05:48,610 --> 00:05:46,130 Hubble observations or alternative 152 00:05:51,100 --> 00:05:48,620 alternatively if you have some adaptive 153 00:05:53,670 --> 00:05:51,110 optics observations from the VLT for 154 00:05:55,719 --> 00:05:53,680 example and with those you can then 155 00:05:57,969 --> 00:05:55,729 individually resolve all these massive 156 00:05:59,499 --> 00:05:57,979 beasts in there and only with these 157 00:06:03,370 --> 00:05:59,509 techniques you can see individual stars 158 00:06:06,189 --> 00:06:03,380 and see and weigh them so what Scott has 159 00:06:08,050 --> 00:06:06,199 up here is what exactly is this the star 160 00:06:10,749 --> 00:06:08,060 cluster itself down on the lower part of 161 00:06:14,260 --> 00:06:10,759 it absolutely exactly so if you look 162 00:06:16,059 --> 00:06:14,270 into that picture maybe for a moment you 163 00:06:18,640 --> 00:06:16,069 can see that all these blue dots that's 164 00:06:21,610 --> 00:06:18,650 the main star cluster we are thinking of 165 00:06:23,830 --> 00:06:21,620 and we're looking at and again this just 166 00:06:25,839 --> 00:06:23,840 this snapshot of the region is in 167 00:06:28,029 --> 00:06:25,849 principle quite huge it's not that small 168 00:06:29,800 --> 00:06:28,039 and we've been only looking into the 169 00:06:31,450 --> 00:06:29,810 very heart of this cluster so if you see 170 00:06:34,570 --> 00:06:31,460 this over dense region this over dense 171 00:06:36,639 --> 00:06:34,580 blue region somewhat in the mid well in 172 00:06:38,610 --> 00:06:36,649 the lower middle that's exactly where 173 00:06:40,110 --> 00:06:38,620 we've been pointing Hubble at 174 00:06:43,860 --> 00:06:40,120 and then we've been looking into the UV 175 00:06:46,890 --> 00:06:43,870 in at least that paper now and we have 176 00:06:48,450 --> 00:06:46,900 more more data coming up soon and trying 177 00:06:50,370 --> 00:06:48,460 to figure out which objects are there 178 00:06:52,830 --> 00:06:50,380 and in fact what they are I mean no one 179 00:06:55,770 --> 00:06:52,840 knew that before at least partly 180 00:06:58,350 --> 00:06:55,780 so you said before before the era of 181 00:07:01,020 --> 00:06:58,360 large telescope space telescopes this 182 00:07:03,510 --> 00:07:01,030 was really so small and unresolved that 183 00:07:05,340 --> 00:07:03,520 people thought it was just one star for 184 00:07:07,050 --> 00:07:05,350 the longest times I right it's 185 00:07:09,030 --> 00:07:07,060 absolutely right and there's another fun 186 00:07:10,680 --> 00:07:09,040 story about that one okay the past 187 00:07:12,570 --> 00:07:10,690 people have been thinking well this is 188 00:07:14,460 --> 00:07:12,580 one star but it's not every what we know 189 00:07:17,010 --> 00:07:14,470 now it's issue a whole star cluster and 190 00:07:21,029 --> 00:07:17,020 then people try to assign one single 191 00:07:23,070 --> 00:07:21,039 mass to this app and star in in in the 192 00:07:25,710 --> 00:07:23,080 region and they came up with the mass of 193 00:07:29,400 --> 00:07:25,720 several times thousands of yeah or that 194 00:07:31,170 --> 00:07:29,410 of a son for a son so it was huge in the 195 00:07:33,629 --> 00:07:31,180 past but then people were able to evolve 196 00:07:35,909 --> 00:07:33,639 it with interferometry and now we're 197 00:07:37,830 --> 00:07:35,919 able to look into it with Hubble and see 198 00:07:39,689 --> 00:07:37,840 its many many many objects but still 199 00:07:41,460 --> 00:07:39,699 it's a thing for fun part of the whole 200 00:07:44,640 --> 00:07:41,470 story you still have the most massive 201 00:07:46,290 --> 00:07:44,650 beast sitting in that cluster no well 202 00:07:52,770 --> 00:07:46,300 that's let's get to that also this is a 203 00:07:54,600 --> 00:07:52,780 this is the Paul this is the as as 204 00:07:57,089 --> 00:07:54,610 Fabien was pointing out the largest 205 00:07:58,800 --> 00:07:57,099 galaxy or the this has some pretty large 206 00:08:01,050 --> 00:07:58,810 stars and can you give us some idea of 207 00:08:04,320 --> 00:08:01,060 the kinds of stars that are in the star 208 00:08:06,690 --> 00:08:04,330 cluster so it's a very rich star cluster 209 00:08:08,520 --> 00:08:06,700 it's probably got at least 50,000 or 210 00:08:10,710 --> 00:08:08,530 maybe a hundred thousand stars in there 211 00:08:12,900 --> 00:08:10,720 but the things that we the thing is that 212 00:08:15,060 --> 00:08:12,910 we can see in that image it does blue 213 00:08:17,010 --> 00:08:15,070 glowing white points of light and that 214 00:08:18,870 --> 00:08:17,020 in that kind of concentrated core of 215 00:08:20,719 --> 00:08:18,880 that cluster the cluster itself is only 216 00:08:23,879 --> 00:08:20,729 a few light-years across 217 00:08:27,420 --> 00:08:23,889 but it's already got you know maybe 218 00:08:29,070 --> 00:08:27,430 50,000 or 100,000 stars within it it's a 219 00:08:30,930 --> 00:08:29,080 bit like an iceberg you know the things 220 00:08:32,159 --> 00:08:30,940 we see just the tip of the iceberg the 221 00:08:34,709 --> 00:08:32,169 things we should dominating the light 222 00:08:37,260 --> 00:08:34,719 it's the most massive stars which give 223 00:08:39,449 --> 00:08:37,270 off the most radiation and this is like 224 00:08:42,329 --> 00:08:39,459 this is a Hubble wide field three 225 00:08:45,690 --> 00:08:42,339 composite image of this central region 226 00:08:48,660 --> 00:08:45,700 of the 32 Ardis region within the Large 227 00:08:50,310 --> 00:08:48,670 Magellanic Cloud so it's a the way I 228 00:08:51,690 --> 00:08:50,320 like to kind of picture it is it the 229 00:08:54,210 --> 00:08:51,700 whole magic 230 00:08:57,150 --> 00:08:54,220 the whole tarantula nebula on the sky 231 00:08:59,190 --> 00:08:57,160 spans about the same angular extent of 232 00:09:01,350 --> 00:08:59,200 the Orion Nebula in our own Milky Way 233 00:09:03,510 --> 00:09:01,360 it's a hunt it's a hundred times further 234 00:09:07,110 --> 00:09:03,520 away so it's actually a hundred times 235 00:09:08,490 --> 00:09:07,120 bigger than the Orion Nebula so there's 236 00:09:09,570 --> 00:09:08,500 probably a couple hundred thousand stars 237 00:09:11,610 --> 00:09:09,580 in the entire nebula 238 00:09:15,170 --> 00:09:11,620 and maybe fifty thousand within that 239 00:09:17,820 --> 00:09:15,180 central few parsec a few light-years 240 00:09:21,210 --> 00:09:17,830 within within our 1:36 itself and our 241 00:09:22,530 --> 00:09:21,220 3:6 was once thought to be a star and 242 00:09:26,910 --> 00:09:22,540 then it was resolved into three 243 00:09:28,890 --> 00:09:26,920 components a B and C and and then later 244 00:09:30,930 --> 00:09:28,900 on it was in broken-down the component a 245 00:09:32,490 --> 00:09:30,940 which is the cluster itself has been 246 00:09:34,740 --> 00:09:32,500 broken down initially into an eight 247 00:09:37,350 --> 00:09:34,750 components and in fact we now know of 248 00:09:40,710 --> 00:09:37,360 many many stars in there and these the 249 00:09:42,180 --> 00:09:40,720 most massive stars the ones which which 250 00:09:44,010 --> 00:09:42,190 we were basically observing in 251 00:09:47,940 --> 00:09:44,020 ultraviolet we looked at we found 252 00:09:50,730 --> 00:09:47,950 several dozen stars with masses of at 253 00:09:53,160 --> 00:09:50,740 least 50 times the mass of the Sun so 254 00:09:57,030 --> 00:09:53,170 these are the kind of very very luminous 255 00:09:58,740 --> 00:09:57,040 may be each of them emitting maybe a 256 00:10:00,420 --> 00:09:58,750 hundred thousand five hundred thousand 257 00:10:02,580 --> 00:10:00,430 or sometimes a million times more than 258 00:10:04,770 --> 00:10:02,590 the Sun these are extremely hot and very 259 00:10:06,900 --> 00:10:04,780 blue stars and that's why they look kind 260 00:10:08,550 --> 00:10:06,910 of bluey white in that picture okay I 261 00:10:11,220 --> 00:10:08,560 want to get more in depth into the stars 262 00:10:12,990 --> 00:10:11,230 themselves in just a minute but someone 263 00:10:15,840 --> 00:10:13,000 can you help me get some idea of the 264 00:10:17,340 --> 00:10:15,850 topology what this image shows a lot 265 00:10:19,200 --> 00:10:17,350 more than just the star cluster is the 266 00:10:22,710 --> 00:10:19,210 entire thing that we're looking at here 267 00:10:25,170 --> 00:10:22,720 the Scott has up is all of this star 268 00:10:27,150 --> 00:10:25,180 forming region the the gas and the the 269 00:10:29,850 --> 00:10:27,160 other of the dust and everything else 270 00:10:31,740 --> 00:10:29,860 all around it what help me understand 271 00:10:34,140 --> 00:10:31,750 this topology here I know what the 272 00:10:36,390 --> 00:10:34,150 cluster is like see that but it is also 273 00:10:38,430 --> 00:10:36,400 these blue stars you know just a little 274 00:10:41,100 --> 00:10:38,440 bit higher up are they part of the same 275 00:10:44,070 --> 00:10:41,110 cluster and then what role do these if 276 00:10:45,900 --> 00:10:44,080 any of these clouds play so these clouds 277 00:10:48,510 --> 00:10:45,910 are where we think stars are being 278 00:10:51,210 --> 00:10:48,520 formed so before this cluster that was 279 00:10:52,860 --> 00:10:51,220 was here there were only clouds it would 280 00:10:55,230 --> 00:10:52,870 be a little hard to see them now we see 281 00:10:56,760 --> 00:10:55,240 them because they're heated up by the by 282 00:10:59,550 --> 00:10:56,770 the stars around them they shape them 283 00:11:03,090 --> 00:10:59,560 you cannot see it too well but the stars 284 00:11:04,800 --> 00:11:03,100 they shine with such strong radiation 285 00:11:05,160 --> 00:11:04,810 that they actually shape it into the 286 00:11:07,829 --> 00:11:05,170 form 287 00:11:10,050 --> 00:11:07,839 fingers and filaments so on the top for 288 00:11:13,470 --> 00:11:10,060 example you see some of the structures 289 00:11:15,150 --> 00:11:13,480 in these clouds it looks like smoke but 290 00:11:18,810 --> 00:11:15,160 it's actually there's new stars being 291 00:11:20,550 --> 00:11:18,820 formed in that region and so as soon as 292 00:11:24,210 --> 00:11:20,560 the stars become so hot that they can 293 00:11:25,860 --> 00:11:24,220 blow off these gas clouds nearby that's 294 00:11:28,259 --> 00:11:25,870 the part where we start to see them so 295 00:11:29,819 --> 00:11:28,269 the blue stars in the very middle you 296 00:11:32,340 --> 00:11:29,829 see they have cleared out most of the 297 00:11:33,569 --> 00:11:32,350 area around them they might be part of 298 00:11:35,189 --> 00:11:33,579 the star cluster and you see outer 299 00:11:37,259 --> 00:11:35,199 layers they may be part of the 300 00:11:39,360 --> 00:11:37,269 surroundings it's a little hard to tell 301 00:11:41,670 --> 00:11:39,370 we know that the star cluster is also 302 00:11:44,220 --> 00:11:41,680 shooting out stars into the environment 303 00:11:46,740 --> 00:11:44,230 so stars do not stay in the same place 304 00:11:49,710 --> 00:11:46,750 when they live their lives so so this is 305 00:11:52,740 --> 00:11:49,720 really active if we could magically 306 00:11:56,280 --> 00:11:52,750 somehow put a camera let's say off to 90 307 00:11:59,189 --> 00:11:56,290 degrees of this nebula would we see kind 308 00:12:00,900 --> 00:11:59,199 of a cave or a blown-out region where 309 00:12:02,490 --> 00:12:00,910 this is kind of a bowl because remember 310 00:12:03,870 --> 00:12:02,500 when we did those we've seen those fly 311 00:12:05,100 --> 00:12:03,880 throughs at least the ones that Frank 312 00:12:08,009 --> 00:12:05,110 summers have made with the Hubble stuff 313 00:12:10,470 --> 00:12:08,019 on the m42 the Orion Nebula we've seen 314 00:12:12,630 --> 00:12:10,480 these sort of blown out bowl of the 315 00:12:13,769 --> 00:12:12,640 Orion Nebula where the stars have formed 316 00:12:16,949 --> 00:12:13,779 employment where we see something like 317 00:12:20,939 --> 00:12:16,959 that maybe here's a one big twisties I 318 00:12:22,470 --> 00:12:20,949 would say okay well compared to the 319 00:12:24,180 --> 00:12:22,480 Orion Nebula and I know that Paul you 320 00:12:25,620 --> 00:12:24,190 alluded to this and and I think I might 321 00:12:27,810 --> 00:12:25,630 have gotten distracted when you said the 322 00:12:30,540 --> 00:12:27,820 difference but how does this region and 323 00:12:33,000 --> 00:12:30,550 this nebula compare with the Orion 324 00:12:35,430 --> 00:12:33,010 Nebula you said it's much much larger is 325 00:12:37,259 --> 00:12:35,440 that right yeah the whole region is 326 00:12:38,910 --> 00:12:37,269 around a hundred times bigger it's it's 327 00:12:40,889 --> 00:12:38,920 about the same angular size bigger okay 328 00:12:42,960 --> 00:12:40,899 yeah hundred times bigger this is 329 00:12:46,740 --> 00:12:42,970 probably a central part of the tarantula 330 00:12:48,840 --> 00:12:46,750 so it's a central half or so or third of 331 00:12:51,240 --> 00:12:48,850 the whole tarantula nebula so it's about 332 00:12:53,699 --> 00:12:51,250 overall 20 was around the 100 times 333 00:12:57,120 --> 00:12:53,709 bigger with a hundred times more stars 334 00:12:59,280 --> 00:12:57,130 than your eye nebula and it's also about 335 00:13:01,410 --> 00:12:59,290 a thousand times brighter the Kista star 336 00:13:03,150 --> 00:13:01,420 as a minute some of the stars are much 337 00:13:04,500 --> 00:13:03,160 hotter than those in your mind negative 338 00:13:06,629 --> 00:13:04,510 so if you put them two at the same 339 00:13:09,030 --> 00:13:06,639 distance you know it would be a thousand 340 00:13:10,769 --> 00:13:09,040 times brighter and it would be a hundred 341 00:13:12,540 --> 00:13:10,779 times larger on the sky if we put a 342 00:13:15,030 --> 00:13:12,550 distance of the Orion Nebula which was 343 00:13:17,260 --> 00:13:15,040 only you know five hundred parsec away 344 00:13:20,170 --> 00:13:17,270 one and a half thousand light-years 345 00:13:21,970 --> 00:13:20,180 much much richer staffing region but 346 00:13:23,890 --> 00:13:21,980 it's I'll guess it's comparisons more 347 00:13:26,380 --> 00:13:23,900 with the Orion molecular cloud from 348 00:13:29,050 --> 00:13:26,390 which the stars are form that's a much 349 00:13:31,530 --> 00:13:29,060 larger region around the nebula that we 350 00:13:34,060 --> 00:13:31,540 can that the famous nebula there's much 351 00:13:35,320 --> 00:13:34,070 extending well past the constellation 352 00:13:36,700 --> 00:13:35,330 boundaries itself now the reason we're 353 00:13:38,890 --> 00:13:36,710 talking about this folks is that the 354 00:13:40,960 --> 00:13:38,900 Orion Nebula is a star forming region 355 00:13:42,400 --> 00:13:40,970 within our own galaxy and so there's a 356 00:13:44,560 --> 00:13:42,410 lot of stars going on there 357 00:13:46,810 --> 00:13:44,570 all of our BR being born there but as 358 00:13:48,580 --> 00:13:46,820 polish's pointing out the kinds of stars 359 00:13:50,500 --> 00:13:48,590 and just a magnitude of the whole thing 360 00:13:52,870 --> 00:13:50,510 it's much much greater in the large 361 00:13:55,750 --> 00:13:52,880 magellanic cloud so you said earlier 362 00:13:57,790 --> 00:13:55,760 that there was different components to 363 00:13:59,530 --> 00:13:57,800 this it was a and a B component was that 364 00:14:01,630 --> 00:13:59,540 just because telescopes got better at 365 00:14:05,740 --> 00:14:01,640 resolving this area and we could see it 366 00:14:09,100 --> 00:14:05,750 more for what it was or yes around about 367 00:14:11,380 --> 00:14:09,110 60 years ago that it was first 368 00:14:14,190 --> 00:14:11,390 identified as a a bright star within 369 00:14:17,080 --> 00:14:14,200 that within the Large Magellanic Cloud 370 00:14:19,120 --> 00:14:17,090 with one three six and then it was in 371 00:14:21,040 --> 00:14:19,130 the 80s where it was then resolved into 372 00:14:23,170 --> 00:14:21,050 three components a B C and then 373 00:14:26,440 --> 00:14:23,180 component a it turned out to be the 374 00:14:29,200 --> 00:14:26,450 cluster was then in the mid eighties we 375 00:14:31,180 --> 00:14:29,210 thought into a number of components but 376 00:14:32,680 --> 00:14:31,190 really if you could see if you could 377 00:14:34,870 --> 00:14:32,690 resolve all the stars you would find 378 00:14:36,910 --> 00:14:34,880 many many tens of thousands of 379 00:14:38,470 --> 00:14:36,920 components in there it's just the right 380 00:14:42,100 --> 00:14:38,480 ones and ones that shine the brightest 381 00:14:44,530 --> 00:14:42,110 they're easy easy to see okay well so 382 00:14:47,050 --> 00:14:44,540 astro girl one USA hello welcome back 383 00:14:48,250 --> 00:14:47,060 I'm glad to see you're back again I was 384 00:14:50,920 --> 00:14:48,260 asking a relevant question what we're 385 00:14:53,350 --> 00:14:50,930 talking about how bright is it now I 386 00:14:55,480 --> 00:14:53,360 assume by that she saw my the magnitude 387 00:14:57,340 --> 00:14:55,490 let's pretend that it's just the one 388 00:14:59,740 --> 00:14:57,350 star thirty-two Radice or whatever and 389 00:15:02,020 --> 00:14:59,750 what would be the brightness of this 390 00:15:03,730 --> 00:15:02,030 thing and maybe is a beam is there 391 00:15:06,970 --> 00:15:03,740 something you can answer for us yeah 392 00:15:09,550 --> 00:15:06,980 sure so individually if you if it 393 00:15:11,320 --> 00:15:09,560 speaking of one of the most brightest 394 00:15:13,930 --> 00:15:11,330 most massive objects in there it can 395 00:15:15,520 --> 00:15:13,940 easily be millions or the luminosity of 396 00:15:18,610 --> 00:15:15,530 this object can be 1 million times that 397 00:15:20,410 --> 00:15:18,620 of our Sun and even above that so it's 398 00:15:23,440 --> 00:15:20,420 one individual object and now you can 399 00:15:26,470 --> 00:15:23,450 count well we have plenty of them say 50 400 00:15:29,770 --> 00:15:26,480 all of that at all of magnitude so the 401 00:15:30,490 --> 00:15:29,780 whole cluster itself can go up to 12 10 402 00:15:34,720 --> 00:15:30,500 to the 7 403 00:15:38,140 --> 00:15:34,730 solar luminosities so it's really you 404 00:15:39,460 --> 00:15:38,150 seven zeroes behind it and it's you know 405 00:15:42,820 --> 00:15:39,470 city you get can get from the cluster 406 00:15:44,830 --> 00:15:42,830 itself yeah okay so the way I and also 407 00:15:46,360 --> 00:15:44,840 interpret this is if I'm an old amateur 408 00:15:52,750 --> 00:15:46,370 astronomer and let me just get rid of 409 00:15:56,350 --> 00:15:52,760 that I'm an amateur astronomer and okay 410 00:15:58,780 --> 00:15:56,360 yeah and if I wanted to look at this 411 00:15:59,860 --> 00:15:58,790 through a telescope from my backyard 412 00:16:10,990 --> 00:15:59,870 could I 413 00:16:13,210 --> 00:16:11,000 or is it to dim the look all day and 414 00:16:15,490 --> 00:16:13,220 night long Tony but unless I can see 415 00:16:20,290 --> 00:16:15,500 through the earth I'm so glad you're 416 00:16:22,360 --> 00:16:20,300 here Scott right so if I were it like 417 00:16:24,700 --> 00:16:22,370 let's say I'm in Chile but I'm not up in 418 00:16:26,590 --> 00:16:24,710 the Andes and I want to look at this 419 00:16:28,660 --> 00:16:26,600 could I yeah what I'd be able to see in 420 00:16:30,610 --> 00:16:28,670 an amateur scope oh you would even see 421 00:16:32,320 --> 00:16:30,620 it with a bear I yeah that's the source 422 00:16:33,550 --> 00:16:32,330 that bright good that's that's sort of 423 00:16:36,910 --> 00:16:33,560 where I was going with that thank you 424 00:16:38,410 --> 00:16:36,920 Scott for making me uh well didn't come 425 00:16:40,450 --> 00:16:38,420 in the whole thing I'm just I'm just 426 00:16:41,940 --> 00:16:40,460 saying yeah I know I let you let that go 427 00:16:45,370 --> 00:16:41,950 so I should be counting my blessed 428 00:16:48,970 --> 00:16:45,380 okay so let's not really lesser in this 429 00:16:54,720 --> 00:16:48,980 group I got a comment here from Paul 430 00:16:57,460 --> 00:16:54,730 from astronomy in Jake Ombuds 431 00:16:59,860 --> 00:16:57,470 themselves in the galaxy cluster or in 432 00:17:01,360 --> 00:16:59,870 the star cluster and as we've you've 433 00:17:03,520 --> 00:17:01,370 already pointed out they're extremely 434 00:17:05,650 --> 00:17:03,530 bright they're they're much much larger 435 00:17:07,780 --> 00:17:05,660 or much more massive than the Sun in 436 00:17:12,460 --> 00:17:07,790 just about every single way they're all 437 00:17:14,170 --> 00:17:12,470 very blue which means give us an idea 438 00:17:16,660 --> 00:17:14,180 about first of all I want to know why 439 00:17:18,160 --> 00:17:16,670 they're blue and I know then that you're 440 00:17:20,140 --> 00:17:18,170 gonna tell me why the Hubble Space 441 00:17:22,210 --> 00:17:20,150 Telescope was able to get such clear 442 00:17:24,280 --> 00:17:22,220 pictures of this and maybe can you give 443 00:17:26,520 --> 00:17:24,290 us a sort of a quick quick rundown on 444 00:17:29,320 --> 00:17:26,530 why these stars are blue and and 445 00:17:32,680 --> 00:17:29,330 basically the the classification of 446 00:17:34,990 --> 00:17:32,690 stars that are in this mmm so I think 447 00:17:37,510 --> 00:17:35,000 the easiest way to explain that is by 448 00:17:39,190 --> 00:17:37,520 looking at a normal flame so if you if 449 00:17:41,080 --> 00:17:39,200 you look at a flame where this hottest 450 00:17:42,580 --> 00:17:41,090 it looks as if it was balloon right and 451 00:17:44,390 --> 00:17:42,590 then the flame gets maybe a bit cooler 452 00:17:45,710 --> 00:17:44,400 to the outside and it's getting 453 00:17:48,320 --> 00:17:45,720 I gather and together and maybe orange 454 00:17:50,510 --> 00:17:48,330 maybe some yellow inside and the star is 455 00:17:52,370 --> 00:17:50,520 nothing but like a flame in principle 456 00:17:54,440 --> 00:17:52,380 it's a blackbody as we would call it and 457 00:17:57,110 --> 00:17:54,450 so it's temperature on the surface tells 458 00:17:58,490 --> 00:17:57,120 what colored will have and these objects 459 00:18:00,350 --> 00:17:58,500 are very massive meaning they're 460 00:18:03,650 --> 00:18:00,360 extremely hot so on the surfaces we 461 00:18:07,130 --> 00:18:03,660 speak of say 50 thousand Kelvin or 50 462 00:18:08,510 --> 00:18:07,140 thousand degrees Celsius and that's its 463 00:18:09,080 --> 00:18:08,520 temperature and if you convert it into 464 00:18:11,660 --> 00:18:09,090 colors 465 00:18:13,820 --> 00:18:11,670 it is blue or in fact these objects 466 00:18:15,470 --> 00:18:13,830 would peak in the ultraviolet which we 467 00:18:17,900 --> 00:18:15,480 fortunately can't see and which you 468 00:18:24,830 --> 00:18:17,910 wouldn't see on earth our atmosphere is 469 00:18:26,570 --> 00:18:24,840 luckily and healthy right yep and so for 470 00:18:28,220 --> 00:18:26,580 us they look blue but if you really look 471 00:18:30,020 --> 00:18:28,230 at where they have their maximum in 472 00:18:32,630 --> 00:18:30,030 radiation it's somewhere over elephant 473 00:18:34,570 --> 00:18:32,640 now as carol has pointed out and if she 474 00:18:36,950 --> 00:18:34,580 were here I'm sure would do so again 475 00:18:39,140 --> 00:18:36,960 really Space Telescope's I think it was 476 00:18:42,670 --> 00:18:39,150 you Paul that pointed out that the ELT 477 00:18:45,710 --> 00:18:42,680 the extremely large telescope run by ESO 478 00:18:47,450 --> 00:18:45,720 the European Southern Observatory would 479 00:18:49,400 --> 00:18:47,460 be able to resolve the stars but not 480 00:18:51,890 --> 00:18:49,410 necessary I wouldn't be able to see this 481 00:18:55,610 --> 00:18:51,900 in the UV because it's a ground-based 482 00:18:58,340 --> 00:18:55,620 telescope so Hubble is one is the only 483 00:19:00,290 --> 00:18:58,350 game in town I'm told by Carol that if 484 00:19:02,600 --> 00:19:00,300 you want to get UV observations you have 485 00:19:05,120 --> 00:19:02,610 to go to Hubble and describe for me a 486 00:19:07,420 --> 00:19:05,130 little bit of Fabien how with what 487 00:19:09,980 --> 00:19:07,430 instrument you got these observations 488 00:19:12,260 --> 00:19:09,990 all right I'll try to explain that I 489 00:19:14,210 --> 00:19:12,270 guess Paul is the expert is all fair ok 490 00:19:15,680 --> 00:19:14,220 well then let me it's no problem I can 491 00:19:17,630 --> 00:19:15,690 you can start and you can kick in yeah 492 00:19:20,150 --> 00:19:17,640 you have to do this I'm asking home 493 00:19:21,650 --> 00:19:20,160 person you guys say now give that one a 494 00:19:23,900 --> 00:19:21,660 call 495 00:19:27,160 --> 00:19:23,910 well the instrument itself is quotes dis 496 00:19:30,080 --> 00:19:27,170 which is when Hubble it's in there in 497 00:19:31,550 --> 00:19:30,090 interferometer and so a spectrograph and 498 00:19:34,340 --> 00:19:31,560 what you do with that is you just have 499 00:19:36,350 --> 00:19:34,350 slits on the sky and in each slit you 500 00:19:38,510 --> 00:19:36,360 take a spectrograph of all the objects 501 00:19:40,250 --> 00:19:38,520 so we oriented all those slits on to the 502 00:19:43,040 --> 00:19:40,260 sky such that in each slit we would have 503 00:19:46,340 --> 00:19:43,050 a couple of stars and then took Hubble 504 00:19:48,260 --> 00:19:46,350 to get all their spectra and that's yeah 505 00:19:49,730 --> 00:19:48,270 what we can get from that and then of 506 00:19:51,620 --> 00:19:49,740 course with a spectrograph or with the 507 00:19:53,480 --> 00:19:51,630 spectrum of the star you have a lot of 508 00:19:56,240 --> 00:19:53,490 information available in particular from 509 00:19:58,280 --> 00:19:56,250 the UV range it's telling a lot of about 510 00:19:59,870 --> 00:19:58,290 the details of the objects 511 00:20:02,000 --> 00:19:59,880 for example what kind of winds they have 512 00:20:04,820 --> 00:20:02,010 how fast the wind is escaping from the 513 00:20:07,370 --> 00:20:04,830 surfaces and so on and so forth okay so 514 00:20:09,980 --> 00:20:07,380 the so by the way still stands for the 515 00:20:12,530 --> 00:20:09,990 Space Telescope imaging spectrograph and 516 00:20:14,240 --> 00:20:12,540 it takes images and spectra at the same 517 00:20:16,430 --> 00:20:14,250 time and of course the Hubble has 518 00:20:18,560 --> 00:20:16,440 ultraviolet filters onboard that lets 519 00:20:21,170 --> 00:20:18,570 you see in these wavelengths so a Selma 520 00:20:23,780 --> 00:20:21,180 I know so we've talked about the colors 521 00:20:25,370 --> 00:20:23,790 of these stars and Polly's told us about 522 00:20:27,890 --> 00:20:25,380 how large they are things like that I 523 00:20:29,990 --> 00:20:27,900 want to know and I I want to know first 524 00:20:34,030 --> 00:20:30,000 of all how how do they get this big it 525 00:20:37,370 --> 00:20:34,040 what's so special about this about this 526 00:20:39,770 --> 00:20:37,380 cluster that makes such enormous stars I 527 00:20:42,320 --> 00:20:39,780 mean is there anything how they get this 528 00:20:44,270 --> 00:20:42,330 way oh you're asking the right question 529 00:20:48,050 --> 00:20:44,280 this is the question this is the big 530 00:20:49,490 --> 00:20:48,060 question for big box yeah it's the 531 00:20:51,410 --> 00:20:49,500 question we don't know the answer to and 532 00:20:53,360 --> 00:20:51,420 that's why we're so well excited to find 533 00:20:55,040 --> 00:20:53,370 them it's a it's frightening for for a 534 00:20:57,140 --> 00:20:55,050 theorist we don't know how such massive 535 00:20:59,420 --> 00:20:57,150 stars form because when you're forming 536 00:21:01,310 --> 00:20:59,430 them they are already so hot that they 537 00:21:03,380 --> 00:21:01,320 they already start to radiate before you 538 00:21:06,410 --> 00:21:03,390 before they have grown so massive and so 539 00:21:08,660 --> 00:21:06,420 all theoretical models that are trying 540 00:21:11,900 --> 00:21:08,670 to explain how you can make such massive 541 00:21:13,580 --> 00:21:11,910 stars they're failing so it's extremely 542 00:21:16,670 --> 00:21:13,590 interesting problem if you're in a 543 00:21:18,500 --> 00:21:16,680 theoretical astrophysicist Paul Crowther 544 00:21:20,120 --> 00:21:18,510 takes the observations there there we 545 00:21:21,500 --> 00:21:20,130 better try to understand when you see em 546 00:21:22,790 --> 00:21:21,510 you know they're there but so you're 547 00:21:26,150 --> 00:21:22,800 saying we've also you know on astronomy 548 00:21:27,710 --> 00:21:26,160 101 we've learned if you take if you go 549 00:21:31,040 --> 00:21:27,720 to university and you take your first 550 00:21:34,490 --> 00:21:31,050 class in stellar evolution you will take 551 00:21:36,230 --> 00:21:34,500 a very easy calculation and you will 552 00:21:38,150 --> 00:21:36,240 calculate yourself that is impossible to 553 00:21:41,510 --> 00:21:38,160 make any star above about 100 solar 554 00:21:43,310 --> 00:21:41,520 masses and then cool Crowther comes 555 00:21:44,930 --> 00:21:43,320 along and tells us well I have all these 556 00:21:46,340 --> 00:21:44,940 stars that are hundred fifty two hundred 557 00:21:49,070 --> 00:21:46,350 and Amy tells us they're born with 558 00:21:51,740 --> 00:21:49,080 around 300 so it's it's it's really 559 00:21:53,750 --> 00:21:51,750 turning a lot of our field around they 560 00:21:56,000 --> 00:21:53,760 don't get that way later they're born at 561 00:21:58,070 --> 00:21:56,010 this eyes okay so it turns out that that 562 00:21:59,420 --> 00:21:58,080 that simple exercise we do in the first 563 00:22:01,220 --> 00:21:59,430 year when you come to the University was 564 00:22:02,480 --> 00:22:01,230 a little bit simplified and so if you 565 00:22:04,280 --> 00:22:02,490 think about the details it's not 566 00:22:07,160 --> 00:22:04,290 impossible that there would be stars 567 00:22:09,380 --> 00:22:07,170 existing that are so massive but still 568 00:22:11,899 --> 00:22:09,390 we have no idea how so much gas can 569 00:22:13,489 --> 00:22:11,909 actually collect and make such a star 570 00:22:15,859 --> 00:22:13,499 and so we're trying to think of creative 571 00:22:17,599 --> 00:22:15,869 ways to find them and so one of the 572 00:22:19,819 --> 00:22:17,609 things you see we apparently find them 573 00:22:23,119 --> 00:22:19,829 only in very dense cluster like this and 574 00:22:25,519 --> 00:22:23,129 so one of the ideas that also Fabian and 575 00:22:27,499 --> 00:22:25,529 we have worked on is maybe these stars 576 00:22:29,659 --> 00:22:27,509 are not formed as normal stars but you 577 00:22:31,819 --> 00:22:29,669 can make them when you smash more than 578 00:22:34,729 --> 00:22:31,829 one star into each other so you make 579 00:22:36,769 --> 00:22:34,739 stars that are also massive but not 580 00:22:39,199 --> 00:22:36,779 crazy massive and you maybe make them in 581 00:22:41,029 --> 00:22:39,209 pairs and these pairs later come 582 00:22:45,649 --> 00:22:41,039 together we have an animation that shows 583 00:22:48,979 --> 00:22:45,659 some of this stuff so here we go okay so 584 00:22:52,399 --> 00:22:48,989 described here what what we're seeing so 585 00:22:54,979 --> 00:22:52,409 this is an animation of a star we found 586 00:22:57,049 --> 00:22:54,989 somewhere else in the region and this is 587 00:22:58,879 --> 00:22:57,059 what we call a contact binary is a kind 588 00:23:00,729 --> 00:22:58,889 of a peanut-shaped binary it's two stars 589 00:23:03,349 --> 00:23:00,739 that are actually touching each other 590 00:23:06,079 --> 00:23:03,359 in the kissing yes that's the press 591 00:23:08,989 --> 00:23:06,089 release we had a a few months ago 592 00:23:10,909 --> 00:23:08,999 actually it's not in this cluster but 593 00:23:11,359 --> 00:23:10,919 these two stars are 30 and 30 solar 594 00:23:14,089 --> 00:23:11,369 masses 595 00:23:16,639 --> 00:23:14,099 and we we think they will come together 596 00:23:18,859 --> 00:23:16,649 and make a 60 solar mass star but from 597 00:23:21,499 --> 00:23:18,869 60 is still a long way to make a 200 598 00:23:22,999 --> 00:23:21,509 solar mass star but this might be one of 599 00:23:24,649 --> 00:23:23,009 the ways we can make at least some of 600 00:23:26,079 --> 00:23:24,659 them but it's still a big puzzle it's 601 00:23:28,009 --> 00:23:26,089 not it's not 602 00:23:30,769 --> 00:23:28,019 astronomers are not agreeing that this 603 00:23:32,569 --> 00:23:30,779 is the only way to do it so Lester you 604 00:23:34,639 --> 00:23:32,579 might even merge these ones and and 605 00:23:38,269 --> 00:23:34,649 throw a third star in that passes by too 606 00:23:40,399 --> 00:23:38,279 close and they will eat up be is a real 607 00:23:41,509 --> 00:23:40,409 mess because if you take two of these 608 00:23:43,939 --> 00:23:41,519 things and they have over time 609 00:23:46,430 --> 00:23:43,949 eventually coalesce you've got two star 610 00:23:49,189 --> 00:23:46,440 cores you've got two stellar atmospheres 611 00:23:52,999 --> 00:23:49,199 all coming together to make one large 612 00:23:54,589 --> 00:23:53,009 star I just wow that just I don't even 613 00:23:58,909 --> 00:23:54,599 know what that would you know that would 614 00:24:00,619 --> 00:23:58,919 be a mess what sort of time scales are 615 00:24:03,379 --> 00:24:00,629 we talking about if this were what's 616 00:24:05,719 --> 00:24:03,389 happening how long do you think that 617 00:24:07,609 --> 00:24:05,729 would take so the whole cluster is still 618 00:24:09,680 --> 00:24:07,619 super young in astronomical terms 619 00:24:12,319 --> 00:24:09,690 meaning it's about 1 million years old 620 00:24:13,939 --> 00:24:12,329 that that is extremely young for a for a 621 00:24:15,949 --> 00:24:13,949 star cluster we don't have a many 622 00:24:17,779 --> 00:24:15,959 regions that are that young and so if 623 00:24:20,749 --> 00:24:17,789 stars pass too close if they're getting 624 00:24:23,329 --> 00:24:20,759 this close it will maybe take 10,000 625 00:24:25,430 --> 00:24:23,339 years or so or less if they if they're 626 00:24:25,789 --> 00:24:25,440 deeper in contact it can just take a few 627 00:24:27,859 --> 00:24:25,799 days 628 00:24:30,229 --> 00:24:27,869 to really do the last bit of the merger 629 00:24:32,570 --> 00:24:30,239 okay so this can happen on relatively 630 00:24:33,979 --> 00:24:32,580 short timescales so they get so let's 631 00:24:36,499 --> 00:24:33,989 get to a couple of these questions then 632 00:24:37,700 --> 00:24:36,509 that a word that I'm saying let's get to 633 00:24:41,330 --> 00:24:37,710 the other one that they're from Paul 634 00:24:46,220 --> 00:24:41,340 from astronomy and Jay comm what colors 635 00:24:48,710 --> 00:24:46,230 can stars start their lives as so you as 636 00:24:50,629 --> 00:24:48,720 I understand that you guys are saying 637 00:24:53,710 --> 00:24:50,639 that these stars in particular in this 638 00:24:56,299 --> 00:24:53,720 cluster in r134 these are starting as 639 00:24:59,320 --> 00:24:56,309 incredibly hot and therefore blue star 640 00:25:03,049 --> 00:24:59,330 that's what Fabien was telling us right 641 00:25:05,389 --> 00:25:03,059 yes so say that was probably a phase 642 00:25:07,340 --> 00:25:05,399 where the star started out more in the 643 00:25:09,499 --> 00:25:07,350 cooler Kazim but then very quickly 644 00:25:11,539 --> 00:25:09,509 equated all its mass and it immediately 645 00:25:13,789 --> 00:25:11,549 turns into something blue and short 646 00:25:17,060 --> 00:25:13,799 again on a time scale of stars of course 647 00:25:18,590 --> 00:25:17,070 so if you really think of so what it's 648 00:25:21,769 --> 00:25:18,600 probably the problem of how to define 649 00:25:23,869 --> 00:25:21,779 when a star gets into existence so when 650 00:25:26,060 --> 00:25:23,879 does the life of a star starts we would 651 00:25:27,830 --> 00:25:26,070 typically say well whenever in in the 652 00:25:30,080 --> 00:25:27,840 core and the interior you start to fuse 653 00:25:32,570 --> 00:25:30,090 hydrogen and at that point these stars 654 00:25:33,859 --> 00:25:32,580 are all extremely blue extremely hot but 655 00:25:36,379 --> 00:25:33,869 before that they had an accretion 656 00:25:38,810 --> 00:25:36,389 history and they're probably looking 657 00:25:42,470 --> 00:25:38,820 kind of reddish but we've never seen 658 00:25:44,570 --> 00:25:42,480 such an object forming yet so right so 659 00:25:47,419 --> 00:25:44,580 yeah I keep coming back to this we've 660 00:25:49,220 --> 00:25:47,429 seen the debates that we as someone was 661 00:25:52,070 --> 00:25:49,230 pointing out in astronomy 101 we counted 662 00:25:53,989 --> 00:25:52,080 it a simplified calculation to do this 663 00:25:55,669 --> 00:25:53,999 accretion model of this gas cloud coming 664 00:25:57,409 --> 00:25:55,679 together and forming whatever stars and 665 00:25:59,330 --> 00:25:57,419 I guess you could assume that you know 666 00:26:01,129 --> 00:25:59,340 red dwarf stars would not have started 667 00:26:02,539 --> 00:26:01,139 with this much material probably in a 668 00:26:04,729 --> 00:26:02,549 very remote region of the galaxy or 669 00:26:07,070 --> 00:26:04,739 whatever it is I don't and then the 670 00:26:09,340 --> 00:26:07,080 these stars obviously being break 671 00:26:12,859 --> 00:26:09,350 crowded and very dense and having a rich 672 00:26:15,109 --> 00:26:12,869 set of cross raw materials can create 673 00:26:18,019 --> 00:26:15,119 these very hot large and blue stars but 674 00:26:20,060 --> 00:26:18,029 even that by itself doesn't doesn't 675 00:26:23,119 --> 00:26:20,070 explain why they get so big and so this 676 00:26:25,369 --> 00:26:23,129 one sort of accretion our emerging model 677 00:26:27,080 --> 00:26:25,379 comes in there was another animation 678 00:26:29,450 --> 00:26:27,090 that I saw before the hangout started 679 00:26:32,149 --> 00:26:29,460 though is that relevant here to Selma 680 00:26:33,710 --> 00:26:32,159 with the there was an I don't recall 681 00:26:35,899 --> 00:26:33,720 what it what it said but there was 682 00:26:38,989 --> 00:26:35,909 another animation that you should we 683 00:26:39,740 --> 00:26:38,999 show I think Paul is proposing to show 684 00:26:42,620 --> 00:26:39,750 their compares 685 00:26:44,260 --> 00:26:42,630 between the Sun and Red Dwarf sir oh all 686 00:26:47,480 --> 00:26:44,270 right sure sure 687 00:26:49,070 --> 00:26:47,490 give me mama okay good okay all right I 688 00:26:50,390 --> 00:26:49,080 didn't know I can be please say 689 00:26:52,610 --> 00:26:50,400 something about this so just before 690 00:26:55,580 --> 00:26:52,620 these stars come in contact this is two 691 00:26:59,210 --> 00:26:55,590 two binary stars that are very close you 692 00:27:01,220 --> 00:26:59,220 see they're just system yeah so we think 693 00:27:03,110 --> 00:27:01,230 that most massive stars have companions 694 00:27:05,930 --> 00:27:03,120 like that it's very rarely we find them 695 00:27:09,320 --> 00:27:05,940 alone and so most normal massive stars 696 00:27:11,270 --> 00:27:09,330 are like this and they turn around each 697 00:27:13,130 --> 00:27:11,280 other like a planet around the Sun and 698 00:27:15,760 --> 00:27:13,140 then they start to interact which is 699 00:27:18,740 --> 00:27:15,770 what you just saw you saw one star 700 00:27:21,620 --> 00:27:18,750 throwing material to the other star some 701 00:27:23,000 --> 00:27:21,630 people call this a vampire system so 702 00:27:25,250 --> 00:27:23,010 this is something we think is a very 703 00:27:27,950 --> 00:27:25,260 common in massive stars the interesting 704 00:27:29,660 --> 00:27:27,960 thing is that these stars four hundred 705 00:27:31,850 --> 00:27:29,670 two hundred solar masses as far as we 706 00:27:34,760 --> 00:27:31,860 know now we don't see any companion 707 00:27:36,920 --> 00:27:34,770 which is actually very strange for a 708 00:27:38,240 --> 00:27:36,930 massive star for normal massive stars 709 00:27:41,090 --> 00:27:38,250 all have companions and these most 710 00:27:43,460 --> 00:27:41,100 massive stars so as far as we know today 711 00:27:44,600 --> 00:27:43,470 they don't have companions that kind of 712 00:27:45,710 --> 00:27:44,610 makes sense right I mean if they've 713 00:27:47,630 --> 00:27:45,720 already perished 714 00:27:49,280 --> 00:27:47,640 they've already might they might have 715 00:27:50,600 --> 00:27:49,290 already eaten their companion so one of 716 00:27:52,430 --> 00:27:50,610 the questions here is are they blue 717 00:27:54,620 --> 00:27:52,440 stragglers and yes that's exactly what 718 00:27:57,200 --> 00:27:54,630 we mean if if a star eats its companion 719 00:27:59,840 --> 00:27:57,210 you get a blue star that appears to be 720 00:28:00,890 --> 00:27:59,850 young it struggles behind the other star 721 00:28:02,780 --> 00:28:00,900 it struggles in time 722 00:28:04,160 --> 00:28:02,790 it looks younger than the other star so 723 00:28:05,750 --> 00:28:04,170 yes it's exactly what we call a blue 724 00:28:08,540 --> 00:28:05,760 straggler great that was from Richard 725 00:28:09,890 --> 00:28:08,550 Craig good question okay okay good so I 726 00:28:16,960 --> 00:28:09,900 want to get to their deaths in a minute 727 00:28:24,890 --> 00:28:21,290 Wow look at that so we have not just 728 00:28:26,090 --> 00:28:24,900 impression okay kind of different sizes 729 00:28:29,630 --> 00:28:26,100 of these different styles and the colors 730 00:28:31,430 --> 00:28:29,640 so so most stars in the universe in a 731 00:28:34,190 --> 00:28:31,440 Milky Way and other galaxies are these 732 00:28:35,870 --> 00:28:34,200 red dwarf stars which are not much 733 00:28:38,570 --> 00:28:35,880 bigger than Jupiter and kind of live 734 00:28:40,760 --> 00:28:38,580 forever you know they kind of keep going 735 00:28:42,350 --> 00:28:40,770 on like they're they may faint and so 736 00:28:44,600 --> 00:28:42,360 they like getting through their hydrogen 737 00:28:46,730 --> 00:28:44,610 fuel very quickly and they just keep on 738 00:28:48,260 --> 00:28:46,740 trucking forever you know and then we 739 00:28:51,430 --> 00:28:48,270 have the next size up that's going to 740 00:28:54,830 --> 00:28:51,440 some sort of savage 741 00:28:58,549 --> 00:28:54,840 which are still pretty common in in 742 00:29:00,529 --> 00:28:58,559 galaxies somewhat bigger you know so 10 743 00:29:02,450 --> 00:29:00,539 times bigger than Jupiter hundred times 744 00:29:05,719 --> 00:29:02,460 bigger than the earth these things have 745 00:29:08,269 --> 00:29:05,729 got lifetimes of 10 billion years of 746 00:29:09,680 --> 00:29:08,279 10,000 million years or so and then most 747 00:29:11,930 --> 00:29:09,690 when we think about massive stars in 748 00:29:13,849 --> 00:29:11,940 general it's that kind of kind of bleed 749 00:29:15,320 --> 00:29:13,859 warf so instead it's a dwarf there it's 750 00:29:17,719 --> 00:29:15,330 not a supergiant star but it's only a 751 00:29:19,999 --> 00:29:17,729 few times bigger than the Sun and may 752 00:29:22,969 --> 00:29:20,009 have a mass of 10 times the mass of the 753 00:29:25,999 --> 00:29:22,979 Sun these are pretty pretty rare and 754 00:29:27,440 --> 00:29:26,009 these things exist in um in in the RAI 755 00:29:29,539 --> 00:29:27,450 nebula for example the few of these 756 00:29:31,489 --> 00:29:29,549 things are in there but still pretty 757 00:29:33,830 --> 00:29:31,499 rare and these had lifetimes of many 758 00:29:35,479 --> 00:29:33,840 tens of millions of years and the kind 759 00:29:37,849 --> 00:29:35,489 of most massive stars are ones which are 760 00:29:40,609 --> 00:29:37,859 in that central cluster in the tarantula 761 00:29:44,479 --> 00:29:40,619 in our 36-hour things a bit like that 762 00:29:46,460 --> 00:29:44,489 but that darker blue cartoon showing 763 00:29:48,950 --> 00:29:46,470 showing what we think is right now the 764 00:29:51,409 --> 00:29:48,960 most massive star known and see if these 765 00:29:54,619 --> 00:29:51,419 are these are maybe 20 times bigger than 766 00:29:55,820 --> 00:29:54,629 the Sun but incredibly luminous and 767 00:29:57,259 --> 00:29:55,830 incredibly short-lived 768 00:30:01,009 --> 00:29:57,269 you know the lifetimes to be stars are 769 00:30:03,139 --> 00:30:01,019 only a few million years and so we have 770 00:30:04,789 --> 00:30:03,149 to look in the youngest artists have a 771 00:30:06,979 --> 00:30:04,799 chance of seeing them you know if a 772 00:30:08,479 --> 00:30:06,989 cluster is only a few million years old 773 00:30:09,969 --> 00:30:08,489 it would be too late these guys are 774 00:30:12,019 --> 00:30:09,979 already gone 775 00:30:13,759 --> 00:30:12,029 amazing look I'm sorry look how large 776 00:30:16,009 --> 00:30:13,769 that it was to you and it's because it's 777 00:30:17,299 --> 00:30:16,019 because they they're so they're shining 778 00:30:19,909 --> 00:30:17,309 so brightly you know they're they're 779 00:30:21,859 --> 00:30:19,919 using up their fuel so quickly which is 780 00:30:24,200 --> 00:30:21,869 why they are such short lifetimes you 781 00:30:26,359 --> 00:30:24,210 know so they you know they're they have 782 00:30:28,820 --> 00:30:26,369 a fuel supply of a hundred times the Sun 783 00:30:31,969 --> 00:30:28,830 in terms of its hydrogen but because 784 00:30:35,180 --> 00:30:31,979 they're shining up - it's a cases now 785 00:30:37,639 --> 00:30:35,190 a36 a one we think shines together ten 786 00:30:39,019 --> 00:30:37,649 million times brighter than the Sun you 787 00:30:40,549 --> 00:30:39,029 know it's going through its fuel so 788 00:30:44,899 --> 00:30:40,559 quickly they live fast and die greedy 789 00:30:50,629 --> 00:30:44,909 young okay and there is another graphic 790 00:30:51,739 --> 00:30:50,639 that we had on the as a pie chart I 791 00:30:53,060 --> 00:30:51,749 guess once you go ahead and put that up 792 00:30:56,989 --> 00:30:53,070 Scott and then I'll have 793 00:31:00,250 --> 00:30:56,999 Fabian watch it why don't you describe 794 00:31:02,560 --> 00:31:00,260 or whose is this whose whose 795 00:31:06,039 --> 00:31:02,570 graphic is this yours Paul or whoever 796 00:31:07,870 --> 00:31:06,049 wants to talk about it I'm just I've 797 00:31:11,889 --> 00:31:07,880 made a gun I made it by tired but I let 798 00:31:16,330 --> 00:31:11,899 far beyond the explain explain so much 799 00:31:19,810 --> 00:31:16,340 pie talk to us so the pie chart looks 800 00:31:22,990 --> 00:31:19,820 like a cake someone's getting hungry no 801 00:31:25,810 --> 00:31:23,000 I don't know that would be any help I'm 802 00:31:28,389 --> 00:31:25,820 a little hungry over here hungry oh oh 803 00:31:31,930 --> 00:31:28,399 you can try it Neal afterwards I don't 804 00:31:33,310 --> 00:31:31,940 know well so what was found 805 00:31:35,710 --> 00:31:33,320 what some of it was is what this was 806 00:31:37,240 --> 00:31:35,720 describing is so most of the stars have 807 00:31:38,830 --> 00:31:37,250 you see in the universe massive stars 808 00:31:43,180 --> 00:31:38,840 they all have a companion so they don't 809 00:31:45,940 --> 00:31:43,190 live alone and it turns out that maybe 810 00:31:49,269 --> 00:31:45,950 1/3 of them or 29% as it is written down 811 00:31:51,370 --> 00:31:49,279 in this pie chart now only sort of live 812 00:31:54,070 --> 00:31:51,380 their life without ever seeing their 813 00:31:56,440 --> 00:31:54,080 companion really here to close or doing 814 00:31:58,360 --> 00:31:56,450 anything with it and all the other stars 815 00:31:59,799 --> 00:31:58,370 the other 2/3 they are doing something 816 00:32:02,500 --> 00:31:59,809 with their companions and you've seen 817 00:32:04,810 --> 00:32:02,510 our two animations already for example 818 00:32:07,210 --> 00:32:04,820 if you look in the into the into the 819 00:32:09,009 --> 00:32:07,220 animation we had just before that was 820 00:32:10,930 --> 00:32:09,019 his mass transfer in binary so there was 821 00:32:13,919 --> 00:32:10,940 just this vampire star sucking of 822 00:32:16,210 --> 00:32:13,929 material from from its companion and 823 00:32:17,500 --> 00:32:16,220 these are these stars that we have in 824 00:32:21,100 --> 00:32:17,510 this pie chart on the top right and 825 00:32:23,049 --> 00:32:21,110 bottom right so you see this mass being 826 00:32:25,120 --> 00:32:23,059 transferred and while you transfer mass 827 00:32:26,560 --> 00:32:25,130 or form um object to the other that 828 00:32:28,539 --> 00:32:26,570 means also you are stripping off its 829 00:32:30,700 --> 00:32:28,549 envelope so you revealing all the deep 830 00:32:32,830 --> 00:32:30,710 insights that have been burnt to helium 831 00:32:35,830 --> 00:32:32,840 into other elements and that can then 832 00:32:38,409 --> 00:32:35,840 explode in various ways and then this 833 00:32:40,210 --> 00:32:38,419 mass accretions stream will then as it 834 00:32:41,649 --> 00:32:40,220 was also shown in the animation spin up 835 00:32:43,180 --> 00:32:41,659 the companion because you're not only 836 00:32:46,090 --> 00:32:43,190 transferring mass but also angular 837 00:32:48,549 --> 00:32:46,100 momentum so it's like this ice skater 838 00:32:51,850 --> 00:32:48,559 that it's getting kind of mass now and 839 00:32:53,320 --> 00:32:51,860 then it spins up and that's what these 840 00:32:55,120 --> 00:32:53,330 stars - and then we've seen the other 841 00:32:57,039 --> 00:32:55,130 animation where the two stars get into 842 00:32:59,560 --> 00:32:57,049 contact or the kissing binaries that's a 843 00:33:02,080 --> 00:32:59,570 lower left region of this diagram and 844 00:33:05,019 --> 00:33:02,090 we'll think that roughly well maybe 1/4 845 00:33:07,840 --> 00:33:05,029 of all the stars that are born in Essos 846 00:33:09,639 --> 00:33:07,850 stars as hot messes stars that 1/4 maybe 847 00:33:12,530 --> 00:33:09,649 is merging with their companion and 848 00:33:14,390 --> 00:33:12,540 that's also what we think what could 849 00:33:19,220 --> 00:33:14,400 happened to maybe one or two of these 850 00:33:21,560 --> 00:33:19,230 beasts in our 156 ok well that's that 851 00:33:23,060 --> 00:33:21,570 that leads me now to another question 852 00:33:25,400 --> 00:33:23,070 that this is coming from John Willis on 853 00:33:27,920 --> 00:33:25,410 YouTube he's going he's asking about the 854 00:33:30,620 --> 00:33:27,930 metallicity of the stars and the gas 855 00:33:33,350 --> 00:33:30,630 clouds and if they're you know are they 856 00:33:34,760 --> 00:33:33,360 low or are they high so I probably get 857 00:33:36,350 --> 00:33:34,770 you in on this can you describe to us 858 00:33:39,530 --> 00:33:36,360 what it what it is first of all tell us 859 00:33:41,210 --> 00:33:39,540 what metallicity means and then maybe 860 00:33:42,740 --> 00:33:41,220 talking what are what are the 861 00:33:47,240 --> 00:33:42,750 metallicity of these stars do we know 862 00:33:49,310 --> 00:33:47,250 sure so so astronomers talk about metals 863 00:33:51,620 --> 00:33:49,320 metals what I'm is very different from 864 00:33:55,490 --> 00:33:51,630 what chemists might talk about different 865 00:33:58,430 --> 00:33:55,500 I learned anything which isn't hydrogen 866 00:34:03,530 --> 00:33:58,440 or helium is a metal so it's oxygen 867 00:34:08,060 --> 00:34:03,540 carbon iron nitrogen these elements and 868 00:34:10,370 --> 00:34:08,070 so in in this in our sole neighborhood 869 00:34:13,190 --> 00:34:10,380 the servants composition is mostly 870 00:34:17,180 --> 00:34:13,200 hydrogen helium with one one bit percent 871 00:34:20,440 --> 00:34:17,190 metals it's the same in the Orion Nebula 872 00:34:23,150 --> 00:34:20,450 where those stars are forming only a few 873 00:34:26,450 --> 00:34:23,160 thousand one thousand light years away 874 00:34:29,690 --> 00:34:26,460 in the in the LMC the present-day metal 875 00:34:33,230 --> 00:34:29,700 content is about half that of the solar 876 00:34:36,919 --> 00:34:33,240 neighborhood so it sits below the metal 877 00:34:40,310 --> 00:34:36,929 content of our local parts of Milky Way 878 00:34:43,419 --> 00:34:40,320 but it slowly a factor of two are there 879 00:34:46,130 --> 00:34:43,429 are places where the metal content is a 880 00:34:48,169 --> 00:34:46,140 hundred times lower you know very 881 00:34:50,330 --> 00:34:48,179 extreme places other places where it's a 882 00:34:54,050 --> 00:34:50,340 factor of a few higher but really it's 883 00:34:56,060 --> 00:34:54,060 it's fairly similar to our own part of 884 00:34:57,920 --> 00:34:56,070 the Milky Way a little bit about only a 885 00:34:59,900 --> 00:34:57,930 little bit ok good well where I want to 886 00:35:02,570 --> 00:34:59,910 go with this now is I want we've all 887 00:35:04,130 --> 00:35:02,580 heard about Jay the James Webb Space 888 00:35:06,440 --> 00:35:04,140 Telescope and the fact that it's going 889 00:35:08,540 --> 00:35:06,450 to be looking at the first galaxies and 890 00:35:09,950 --> 00:35:08,550 also the first stars and one of the 891 00:35:11,780 --> 00:35:09,960 things about the very first stars in the 892 00:35:13,250 --> 00:35:11,790 universe is that they are known for 893 00:35:15,200 --> 00:35:13,260 having their very low metallicity 894 00:35:16,700 --> 00:35:15,210 primarily hydrogen and helium and in the 895 00:35:19,490 --> 00:35:16,710 early universe was all they had to work 896 00:35:21,530 --> 00:35:19,500 with and so those stars are they when I 897 00:35:24,080 --> 00:35:21,540 hear you guys talk about the stars in 898 00:35:25,020 --> 00:35:24,090 this cluster it reminds me a lot about 899 00:35:26,610 --> 00:35:25,030 what I've learned 900 00:35:27,990 --> 00:35:26,620 heard about the James Webb Space 901 00:35:30,360 --> 00:35:28,000 Telescope was going to show us for the 902 00:35:32,580 --> 00:35:30,370 first stars and Paul you're just saying 903 00:35:35,220 --> 00:35:32,590 that they are about a factor of two 904 00:35:36,990 --> 00:35:35,230 lowering metallicity from our own but it 905 00:35:38,850 --> 00:35:37,000 sounds to me like there's some pretty 906 00:35:42,210 --> 00:35:38,860 big differences so what can you compare 907 00:35:46,080 --> 00:35:42,220 these stars was with what the very first 908 00:35:47,580 --> 00:35:46,090 stars would be like sure so I mean the 909 00:35:49,320 --> 00:35:47,590 kind of things which Hubble can do right 910 00:35:51,870 --> 00:35:49,330 now we're looking at the these these 911 00:35:53,820 --> 00:35:51,880 very early protocol X's what we call 912 00:35:58,650 --> 00:35:53,830 high redshift where shift of five or so 913 00:36:01,920 --> 00:35:58,660 I can do right now 10h of 10 these are 914 00:36:03,630 --> 00:36:01,930 these are things which I would say the 915 00:36:05,250 --> 00:36:03,640 kind of star formation because there's 916 00:36:06,390 --> 00:36:05,260 an awful lot of gas the star formation 917 00:36:09,450 --> 00:36:06,400 that's going on in those high-redshift 918 00:36:11,160 --> 00:36:09,460 galaxies is to me very similar to 919 00:36:14,580 --> 00:36:11,170 actually what's going on within the kind 920 00:36:16,980 --> 00:36:14,590 of tarantula you know tarantulas a very 921 00:36:20,970 --> 00:36:16,990 violent style forming place compared to 922 00:36:23,670 --> 00:36:20,980 our own very quiet lone star formation 923 00:36:25,260 --> 00:36:23,680 going on in our Milky Way so to me the 924 00:36:27,840 --> 00:36:25,270 tarantula is a good kind of template 925 00:36:30,180 --> 00:36:27,850 really for for typical star formation 926 00:36:31,800 --> 00:36:30,190 going on in these hybrid galaxies but if 927 00:36:33,240 --> 00:36:31,810 you want to go to the first galaxies of 928 00:36:34,950 --> 00:36:33,250 course they're the ones where there's no 929 00:36:36,720 --> 00:36:34,960 metals so you're looking at stars 930 00:36:39,390 --> 00:36:36,730 forming out of purely hydrogen and 931 00:36:43,260 --> 00:36:39,400 helium and we think that those stars are 932 00:36:46,650 --> 00:36:43,270 much more compact than those we see in a 933 00:36:48,420 --> 00:36:46,660 tarantula in our own Milky Way and and 934 00:36:50,850 --> 00:36:48,430 also therefore much more compact much 935 00:36:53,490 --> 00:36:50,860 hotter and we think probably also much 936 00:36:55,080 --> 00:36:53,500 higher mass on average you know that 937 00:36:57,060 --> 00:36:55,090 that image I showed you which showed the 938 00:37:01,980 --> 00:36:57,070 kind of typical Styles being a red dwarf 939 00:37:03,390 --> 00:37:01,990 you know a tenth of a solar mass and we 940 00:37:05,460 --> 00:37:03,400 think that probably the typical stars 941 00:37:07,020 --> 00:37:05,470 forming the first stars forming that 942 00:37:11,010 --> 00:37:07,030 James whoever should be able to kind of 943 00:37:15,780 --> 00:37:11,020 hopefully get get get to are probably 944 00:37:20,370 --> 00:37:15,790 typically the kind of blue more massive 945 00:37:21,990 --> 00:37:20,380 than the Sun so so quite the the messes 946 00:37:24,570 --> 00:37:22,000 we don't quite know what a typical mass 947 00:37:26,850 --> 00:37:24,580 of these first generations of stars are 948 00:37:28,440 --> 00:37:26,860 like well I heard it was more or less 949 00:37:30,660 --> 00:37:28,450 like what we're talking about here 100 950 00:37:32,430 --> 00:37:30,670 200 times yeah that the original 951 00:37:34,200 --> 00:37:32,440 simulation seemed to say typical stars 952 00:37:36,930 --> 00:37:34,210 where maybe a hundred times the mass of 953 00:37:38,299 --> 00:37:36,940 the Sun but the more modern simulations 954 00:37:41,660 --> 00:37:38,309 seem to say may have some way 955 00:37:44,839 --> 00:37:41,670 maybe what water 10 maybe but certainly 956 00:37:46,549 --> 00:37:44,849 those 10 Solomon stars would be much 957 00:37:49,309 --> 00:37:46,559 more compact and therefore emitting a 958 00:37:50,989 --> 00:37:49,319 lot of their energy in the ultraviolet a 959 00:37:53,239 --> 00:37:50,999 bit like these these guys in the 960 00:37:54,799 --> 00:37:53,249 tarantula and of course that light gets 961 00:37:57,289 --> 00:37:54,809 redshifted you know looking at a 962 00:38:00,049 --> 00:37:57,299 redshift 20 galaxies as they shifted out 963 00:38:04,039 --> 00:38:00,059 into the near infrared where where James 964 00:38:06,289 --> 00:38:04,049 Webb will really really explain its 965 00:38:07,999 --> 00:38:06,299 large angular size and collecting area 966 00:38:10,279 --> 00:38:08,009 yeah and I guess that's where the 967 00:38:11,929 --> 00:38:10,289 comparison kind of start because the the 968 00:38:13,579 --> 00:38:11,939 reason James Webb is going to be an 969 00:38:15,109 --> 00:38:13,589 infrared telescope is like you say a lot 970 00:38:17,299 --> 00:38:15,119 of these things that were very bright in 971 00:38:19,699 --> 00:38:17,309 the ultraviolet have red shifted into 972 00:38:22,459 --> 00:38:19,709 the infrared it's not going to be much 973 00:38:24,890 --> 00:38:22,469 help is it for looking at this 974 00:38:26,299 --> 00:38:24,900 particular cluster one if you wouldn't 975 00:38:27,709 --> 00:38:26,309 let's say they launched change web and 976 00:38:30,019 --> 00:38:27,719 one of them somebody comes up with a 977 00:38:33,079 --> 00:38:30,029 proposal I want to look at are 134 with 978 00:38:34,819 --> 00:38:33,089 this I'm what are they gonna see much 979 00:38:38,329 --> 00:38:34,829 are they because this is primarily a UV 980 00:38:40,099 --> 00:38:38,339 target well the most luminous stars are 981 00:38:42,229 --> 00:38:40,109 UV bright but they're still pretty 982 00:38:44,179 --> 00:38:42,239 bright in the infrared we've observed 983 00:38:46,759 --> 00:38:44,189 this cluster with their own eyes 984 00:38:48,859 --> 00:38:46,769 telescope in the infrared and it's got a 985 00:38:53,419 --> 00:38:48,869 similar resorbing similar angular 986 00:38:55,069 --> 00:38:53,429 resolving power to Hubble and so you can 987 00:38:57,319 --> 00:38:55,079 observe these things in the infrared but 988 00:38:59,539 --> 00:38:57,329 of course most of energy is Fabien 989 00:39:02,539 --> 00:38:59,549 mentioned earlier is being pumped out in 990 00:39:04,400 --> 00:39:02,549 the ultraviolet and so Yuri ideally hot 991 00:39:05,839 --> 00:39:04,410 always perfect in terms of looking at 992 00:39:09,079 --> 00:39:05,849 these styles where they're brightest in 993 00:39:10,489 --> 00:39:09,089 the ultraviolet part of the spectrum and 994 00:39:12,289 --> 00:39:10,499 it's only those guys which then when you 995 00:39:14,569 --> 00:39:12,299 look at those in hi Reggie can access 996 00:39:16,009 --> 00:39:14,579 that light gets red shifted out towards 997 00:39:18,650 --> 00:39:16,019 infrared wavelengths which James Webb 998 00:39:20,299 --> 00:39:18,660 will be able to exploit I keep saying 999 00:39:20,809 --> 00:39:20,309 134 I don't know why I do you know why I 1000 00:39:22,789 --> 00:39:20,819 do that 1001 00:39:25,339 --> 00:39:22,799 you know what are 136 reminds me of it 1002 00:39:29,089 --> 00:39:25,349 reminds me of a refrigerant are 134 1003 00:39:32,179 --> 00:39:29,099 which I put in my air conditioner that's 1004 00:39:37,400 --> 00:39:32,189 really like 130 or so my apologies for 1005 00:39:38,929 --> 00:39:37,410 doing that I see are at 130 oh it's a 1006 00:39:41,479 --> 00:39:38,939 little warmer than that just a little 1007 00:39:43,249 --> 00:39:41,489 bit yeah I get that it's yeah so anyway 1008 00:39:45,679 --> 00:39:43,259 that's why I keep doing that I my 1009 00:39:47,299 --> 00:39:45,689 apologies for it for mispronouncing it 1010 00:39:49,640 --> 00:39:47,309 so let's go to the next stage so we know 1011 00:39:52,160 --> 00:39:49,650 these are these are being born in a very 1012 00:39:54,079 --> 00:39:52,170 rich area in the Large Magellanic Cloud 1013 00:39:55,960 --> 00:39:54,089 and nebula we know they're very large we 1014 00:39:59,589 --> 00:39:55,970 don't know quite how they got that big 1015 00:40:03,109 --> 00:39:59,599 but they are that big to 100 250 times 1016 00:40:04,910 --> 00:40:03,119 more massive than our Sun and Jeffrey 1017 00:40:08,120 --> 00:40:04,920 knee is asking is it impossible for a 1018 00:40:10,490 --> 00:40:08,130 star to gather 100 plus solar masses as 1019 00:40:12,680 --> 00:40:10,500 it travels through the nebula and I 1020 00:40:15,440 --> 00:40:12,690 think the answer to that is no cuz 1021 00:40:17,690 --> 00:40:15,450 they're there plenty of men right I mean 1022 00:40:20,329 --> 00:40:17,700 how would you answer that salma yeah 1023 00:40:22,010 --> 00:40:20,339 just gathering it by flying through a 1024 00:40:25,579 --> 00:40:22,020 cloud it's not helping this stars 1025 00:40:28,150 --> 00:40:25,589 shining and so actually it would blow 1026 00:40:30,980 --> 00:40:28,160 off material of the cloud it's shaping 1027 00:40:33,260 --> 00:40:30,990 holes it's making these what I could 1028 00:40:35,180 --> 00:40:33,270 cover Swiss cheese bubbles in these 1029 00:40:37,520 --> 00:40:35,190 clouds so no it cannot accrete it by 1030 00:40:41,270 --> 00:40:37,530 just moving through the crowd so it has 1031 00:40:43,730 --> 00:40:41,280 to get it either at formation or like 1032 00:40:45,710 --> 00:40:43,740 usually when it's reform when it's very 1033 00:40:47,420 --> 00:40:45,720 young when it's not really shining that 1034 00:40:48,770 --> 00:40:47,430 brightly and it's not that hot yet that 1035 00:40:51,349 --> 00:40:48,780 would be the moment when it can maybe 1036 00:40:52,940 --> 00:40:51,359 accrete and it would help over probably 1037 00:40:54,799 --> 00:40:52,950 when it's sitting in a dense center of 1038 00:40:56,150 --> 00:40:54,809 that star cluster and the gravity of all 1039 00:40:59,420 --> 00:40:56,160 these stars together maybe that's 1040 00:41:03,680 --> 00:40:59,430 helping in parts to to attract all these 1041 00:41:05,480 --> 00:41:03,690 gas clouds to fall into the gravity or 1042 00:41:07,490 --> 00:41:05,490 attracted by the gravity of these 1043 00:41:08,829 --> 00:41:07,500 combined stars well I have to ask this 1044 00:41:10,609 --> 00:41:08,839 because we're very enamored with 1045 00:41:14,450 --> 00:41:10,619 exoplanets these days what are the 1046 00:41:16,730 --> 00:41:14,460 planet prospects inside so the James 1047 00:41:18,680 --> 00:41:16,740 Webb is not maybe not I mean we would 1048 00:41:23,210 --> 00:41:18,690 love or UV telescope to be the next 1049 00:41:24,770 --> 00:41:23,220 telescope is gonna do great things for 1050 00:41:26,480 --> 00:41:24,780 for massive stars when they're slightly 1051 00:41:29,000 --> 00:41:26,490 younger and and something else you could 1052 00:41:31,280 --> 00:41:29,010 do if you would look in the infrared 1053 00:41:33,200 --> 00:41:31,290 these stars you would these stars it's 1054 00:41:35,000 --> 00:41:33,210 annoying they're so bright because it's 1055 00:41:37,460 --> 00:41:35,010 very hard to study what are the low mass 1056 00:41:39,140 --> 00:41:37,470 stars right next to it doing so if you 1057 00:41:40,940 --> 00:41:39,150 look in the infrared it would be a 1058 00:41:44,450 --> 00:41:40,950 really nice way to sort of put sun 1059 00:41:45,770 --> 00:41:44,460 shades sunglasses on to make the blue 1060 00:41:47,480 --> 00:41:45,780 stars a little bit dimmer so you can 1061 00:41:49,700 --> 00:41:47,490 actually see the low mass stars next to 1062 00:41:52,099 --> 00:41:49,710 it so I saw there was one question of 1063 00:41:54,530 --> 00:41:52,109 could such a massive star have a planet 1064 00:41:56,900 --> 00:41:54,540 that is unlikely because you need time 1065 00:41:59,780 --> 00:41:56,910 to form a planet and it's not helping if 1066 00:42:01,609 --> 00:41:59,790 the star shining so bright but these 1067 00:42:04,059 --> 00:42:01,619 stars may have tiny tiny little 1068 00:42:06,020 --> 00:42:04,069 companion stars that is kind of planets 1069 00:42:08,870 --> 00:42:06,030 and so it would help to 1070 00:42:11,660 --> 00:42:08,880 looking redder wavelengths to us to look 1071 00:42:13,580 --> 00:42:11,670 for these Lomas companions but I can't 1072 00:42:16,280 --> 00:42:13,590 imagine the environment in that star 1073 00:42:18,740 --> 00:42:16,290 cluster being all that habitable for any 1074 00:42:21,530 --> 00:42:18,750 planet so my feet in there but that's 1075 00:42:24,110 --> 00:42:21,540 just a guess that I would have so okay 1076 00:42:25,520 --> 00:42:24,120 well so we we don't there it's possible 1077 00:42:27,050 --> 00:42:25,530 that there are planets in there there's 1078 00:42:28,910 --> 00:42:27,060 also pot there's certainly lower mass 1079 00:42:30,680 --> 00:42:28,920 stars going on and shining in there as 1080 00:42:32,060 --> 00:42:30,690 well and as someone points out it'd be 1081 00:42:34,790 --> 00:42:32,070 great if we could maybe turn it down a 1082 00:42:38,090 --> 00:42:34,800 notch or two to take a look but it's not 1083 00:42:40,310 --> 00:42:38,100 that's not something we can be right I 1084 00:42:42,020 --> 00:42:40,320 mean as we're seeing here this is the 1085 00:42:43,010 --> 00:42:42,030 same area looking through VLT as we're 1086 00:42:44,990 --> 00:42:43,020 talking about for the Very Large 1087 00:42:47,570 --> 00:42:45,000 Telescope so as we're seeing in that 1088 00:42:49,070 --> 00:42:47,580 class they're just very blown out I'm 1089 00:42:51,770 --> 00:42:49,080 not able to resolve as well as we were 1090 00:42:53,480 --> 00:42:51,780 able to with with Hubble in the UV so 1091 00:42:55,460 --> 00:42:53,490 the cluster is that little dot right in 1092 00:42:57,770 --> 00:42:55,470 the center there is that bright that 1093 00:42:59,270 --> 00:42:57,780 bright dot in the center right so it's a 1094 00:43:01,100 --> 00:42:59,280 little you know a little different what 1095 00:43:03,830 --> 00:43:01,110 we're able to see with the most recent 1096 00:43:05,930 --> 00:43:03,840 one but I saying it is pretty bright in 1097 00:43:09,530 --> 00:43:05,940 infrared but we're not able to resolve 1098 00:43:12,200 --> 00:43:09,540 that stuff in the UV okay all right Tony 1099 00:43:13,760 --> 00:43:12,210 yeah about planets came up and so just 1100 00:43:16,940 --> 00:43:13,770 to give you a sense just to give you the 1101 00:43:19,550 --> 00:43:16,950 people a sense about what if you were a 1102 00:43:21,470 --> 00:43:19,560 planet hypothetical planet orbiting one 1103 00:43:26,480 --> 00:43:21,480 of these guys if you put you know if you 1104 00:43:28,310 --> 00:43:26,490 put the earth the same distance as from 1105 00:43:30,770 --> 00:43:28,320 one three six a one on one is other very 1106 00:43:31,970 --> 00:43:30,780 massive stars as it's from the Sun it 1107 00:43:33,740 --> 00:43:31,980 would it would not if it was to be 1108 00:43:36,620 --> 00:43:33,750 remain bound it would orbit in about 1109 00:43:41,420 --> 00:43:36,630 three weeks sorry yeah would be three 1110 00:43:48,320 --> 00:43:41,430 weeks on gonna make Tony even older than 1111 00:43:50,150 --> 00:43:48,330 he is now yes but the ocean is not to 1112 00:43:51,920 --> 00:43:50,160 boil away we'd have to put the earth 1113 00:43:55,250 --> 00:43:51,930 about a thousand over a thousand times 1114 00:43:56,840 --> 00:43:55,260 further away than the earth is for it 1115 00:43:59,150 --> 00:43:56,850 because there's huge radiation coming 1116 00:44:00,140 --> 00:43:59,160 from the star okay I don't want to go 1117 00:44:02,960 --> 00:44:00,150 off on rent here 1118 00:44:04,280 --> 00:44:02,970 but with with the exoplanets that we've 1119 00:44:06,920 --> 00:44:04,290 been learning about they all seem to 1120 00:44:10,130 --> 00:44:06,930 have these ridiculously short years 1121 00:44:12,590 --> 00:44:10,140 eighteen days two weeks three weeks four 1122 00:44:14,510 --> 00:44:12,600 mean that's just that's just crazy and I 1123 00:44:16,340 --> 00:44:14,520 mean you're right I don't even want to 1124 00:44:19,549 --> 00:44:16,350 think about how old I would be on a 1125 00:44:21,439 --> 00:44:19,559 planet with a year of only 1126 00:44:23,179 --> 00:44:21,449 eighteen days so you could just have all 1127 00:44:25,670 --> 00:44:23,189 that but anyway the calculation to make 1128 00:44:27,069 --> 00:44:25,680 any mess that's not let's just move 1129 00:44:31,309 --> 00:44:27,079 right along 1130 00:44:36,609 --> 00:44:31,319 okay so Fabian I want I want to talk 1131 00:44:45,529 --> 00:44:36,619 about how these stars are gonna die what 1132 00:44:47,120 --> 00:44:45,539 excellent question so we've got these 1133 00:44:49,479 --> 00:44:47,130 stars I don't they're bright they're hot 1134 00:44:52,640 --> 00:44:49,489 they're young they're huge they're 1135 00:44:55,640 --> 00:44:52,650 they're they're running out of fuel very 1136 00:44:57,319 --> 00:44:55,650 quickly the masses imply a lot of really 1137 00:44:58,939 --> 00:44:57,329 cool things when they run out start to 1138 00:45:00,049 --> 00:44:58,949 run out of fuel museum their lives so 1139 00:45:02,900 --> 00:45:00,059 what do you guys think will happen 1140 00:45:05,269 --> 00:45:02,910 exactly so the really interesting bit of 1141 00:45:07,640 --> 00:45:05,279 the Toronto net nebula is that it is at 1142 00:45:09,739 --> 00:45:07,650 a lower metallicity and the lower 1143 00:45:13,219 --> 00:45:09,749 melissa metallicity usually allows for 1144 00:45:15,799 --> 00:45:13,229 really crazy explosions of stars so say 1145 00:45:17,120 --> 00:45:15,809 in our own Milky Way backyard I guess 1146 00:45:19,249 --> 00:45:17,130 what we would have in the end of the 1147 00:45:20,959 --> 00:45:19,259 stellar life is that it's core collapses 1148 00:45:23,299 --> 00:45:20,969 so it's a classical core collapse 1149 00:45:24,979 --> 00:45:23,309 supernova as we would call it so what's 1150 00:45:27,380 --> 00:45:24,989 happening there is the star it's just 1151 00:45:29,269 --> 00:45:27,390 fusing all its fuel so it start our the 1152 00:45:31,130 --> 00:45:29,279 hydrogen convert it into helium and then 1153 00:45:33,049 --> 00:45:31,140 takes the helium further converts it 1154 00:45:35,449 --> 00:45:33,059 into carbon and oxygen and it goes on 1155 00:45:36,859 --> 00:45:35,459 and on and on until you hit a silicon 1156 00:45:39,679 --> 00:45:36,869 burning and the silicon burning is 1157 00:45:42,650 --> 00:45:39,689 converting everything into iron now with 1158 00:45:46,459 --> 00:45:42,660 I and you have a problem from I infusion 1159 00:45:49,759 --> 00:45:46,469 you cannot get any energy out over this 1160 00:45:53,630 --> 00:45:49,769 star is suddenly robbed of its energy 1161 00:45:54,829 --> 00:45:53,640 source and so it has to collapse and and 1162 00:45:57,859 --> 00:45:54,839 this is what we then call a core 1163 00:46:00,410 --> 00:45:57,869 collapse supernova it's a classical way 1164 00:46:03,469 --> 00:46:00,420 of a star to die and at low metallicity 1165 00:46:06,079 --> 00:46:03,479 z-- you have a well one more fancy way 1166 00:46:08,029 --> 00:46:06,089 to die if you like well in fact I would 1167 00:46:10,489 --> 00:46:08,039 say to two further ways that you can die 1168 00:46:11,809 --> 00:46:10,499 and the one is probably the path that we 1169 00:46:13,969 --> 00:46:11,819 would call a long-duration gamma-ray 1170 00:46:15,799 --> 00:46:13,979 burst I will come to that in a second 1171 00:46:17,569 --> 00:46:15,809 and the other one which is also 1172 00:46:20,179 --> 00:46:17,579 extremely fancy as a pair instability 1173 00:46:23,329 --> 00:46:20,189 supernova so let me first discuss his 1174 00:46:25,099 --> 00:46:23,339 parents ability a supernova so what is 1175 00:46:27,650 --> 00:46:25,109 happening here is the star is still 1176 00:46:29,390 --> 00:46:27,660 burning it's its fuel so it's at having 1177 00:46:31,130 --> 00:46:29,400 maybe a lot of helium in its core 1178 00:46:33,500 --> 00:46:31,140 so we're speaking of a core mass now 1179 00:46:35,870 --> 00:46:33,510 that is above say 60 times 1180 00:46:37,609 --> 00:46:35,880 or son just the core of a star so 1181 00:46:41,090 --> 00:46:37,619 there's still an envelope sitting on top 1182 00:46:43,099 --> 00:46:41,100 and once you're hitting them this helium 1183 00:46:46,970 --> 00:46:43,109 burning and later on into the carbon and 1184 00:46:50,000 --> 00:46:46,980 oxygen burning the interior of the star 1185 00:46:53,240 --> 00:46:50,010 is so hot that all its photons or some 1186 00:46:56,390 --> 00:46:53,250 of its photons can produce l2 and 1187 00:46:58,580 --> 00:46:56,400 positron pairs this pair creation and 1188 00:47:00,260 --> 00:46:58,590 you need to know now that this interior 1189 00:47:03,380 --> 00:47:00,270 of such stars is balanced by the 1190 00:47:05,210 --> 00:47:03,390 radiation so they are variation power 1191 00:47:07,460 --> 00:47:05,220 balance to the radiation pressure from 1192 00:47:10,550 --> 00:47:07,470 all the photons in the inside is keeping 1193 00:47:12,109 --> 00:47:10,560 up or battling gravity if you like but 1194 00:47:13,430 --> 00:47:12,119 now you're taking away these photons 1195 00:47:15,200 --> 00:47:13,440 because you're producing a bit of 1196 00:47:16,310 --> 00:47:15,210 electrons and positrons and suddenly 1197 00:47:19,250 --> 00:47:16,320 what's going to happen is that they 1198 00:47:22,010 --> 00:47:19,260 start contracts extremely fast it 1199 00:47:23,660 --> 00:47:22,020 contracts its heat heating up and so 1200 00:47:26,450 --> 00:47:23,670 you're hitting a regime where you have 1201 00:47:28,280 --> 00:47:26,460 an explosive nuclear burning and what it 1202 00:47:30,380 --> 00:47:28,290 really means is that these objects 1203 00:47:33,349 --> 00:47:30,390 everything in it in the inside are going 1204 00:47:35,870 --> 00:47:33,359 to be burned into iron elements and this 1205 00:47:37,460 --> 00:47:35,880 energy release is usually then enough to 1206 00:47:40,430 --> 00:47:37,470 unbind the whole star and you can have 1207 00:47:42,290 --> 00:47:40,440 an extraordinary bright explosion in 1208 00:47:45,859 --> 00:47:42,300 particular you can produce maybe up to 1209 00:47:48,349 --> 00:47:45,869 10 solar masses of nickel and maybe you 1210 00:47:50,390 --> 00:47:48,359 know nickel is a radioactive element so 1211 00:47:52,099 --> 00:47:50,400 it's going to decay and this decay of 1212 00:47:54,230 --> 00:47:52,109 all this tensile amounts of nickel for 1213 00:47:55,940 --> 00:47:54,240 example that is powering a light curve 1214 00:47:57,550 --> 00:47:55,950 and a supernova that is extremely bright 1215 00:48:00,740 --> 00:47:57,560 and that's why we call them 1216 00:48:03,140 --> 00:48:00,750 superluminous supernova yeah give me a 1217 00:48:07,340 --> 00:48:03,150 fancy name but it's one way of for these 1218 00:48:09,349 --> 00:48:07,350 guys to die and so I just want to point 1219 00:48:11,180 --> 00:48:09,359 out also these parent stability 1220 00:48:12,950 --> 00:48:11,190 supernova that you're talking about is 1221 00:48:14,570 --> 00:48:12,960 also what's going to happen to the very 1222 00:48:17,030 --> 00:48:14,580 first stars I mean that's also what 1223 00:48:19,640 --> 00:48:17,040 they're about so again there's a lot of 1224 00:48:21,050 --> 00:48:19,650 parallels between this research and the 1225 00:48:23,000 --> 00:48:21,060 early universe and it all has to do with 1226 00:48:25,670 --> 00:48:23,010 the level of metallicity and stars 1227 00:48:27,109 --> 00:48:25,680 correct exactly I should adhere that at 1228 00:48:29,330 --> 00:48:27,119 the metallicity of the Large Magellanic 1229 00:48:31,580 --> 00:48:29,340 Cloud we do not think that these stars 1230 00:48:33,290 --> 00:48:31,590 are ending up as a pain so pretty superb 1231 00:48:34,550 --> 00:48:33,300 yeah okay go so probably what's going to 1232 00:48:36,140 --> 00:48:34,560 happen is that their stellar winds 1233 00:48:38,030 --> 00:48:36,150 they're too strong so this star is 1234 00:48:40,790 --> 00:48:38,040 losing all its mass so we will never 1235 00:48:43,460 --> 00:48:40,800 have a core mass of helium above this 60 1236 00:48:45,830 --> 00:48:43,470 or 65 solar masses so it cannot go this 1237 00:48:46,880 --> 00:48:45,840 path but if you just go maybe I don't 1238 00:48:49,759 --> 00:48:46,890 know a factor to 1239 00:48:53,450 --> 00:48:49,769 three lower mid Lissa T and it's already 1240 00:48:55,309 --> 00:48:53,460 the regime where you can do it well the 1241 00:48:58,450 --> 00:48:55,319 other one the long location gamma-ray 1242 00:49:02,059 --> 00:48:58,460 bursts it's also really fun thing and 1243 00:49:06,799 --> 00:49:02,069 let that sound fun Fabian because I'll 1244 00:49:12,319 --> 00:49:06,809 tell you in a second why surfing on this 1245 00:49:15,680 --> 00:49:12,329 thing long-duration gamma-ray bursts do 1246 00:49:17,839 --> 00:49:15,690 not sound fun but go ahead go back a 1247 00:49:20,269 --> 00:49:17,849 couple of models out there and in terms 1248 00:49:22,309 --> 00:49:20,279 of what it can can happen but what 1249 00:49:25,130 --> 00:49:22,319 observations suggest nowadays is that 1250 00:49:26,930 --> 00:49:25,140 there is a correlation between massive 1251 00:49:29,420 --> 00:49:26,940 stars exploding and slow innovation 1252 00:49:31,759 --> 00:49:29,430 gamma-ray bursts and one favor or one 1253 00:49:34,160 --> 00:49:31,769 popular model is the so-called collapse 1254 00:49:37,579 --> 00:49:34,170 a model and the interior of the star 1255 00:49:39,019 --> 00:49:37,589 gave to a collapse are exactly so we 1256 00:49:41,539 --> 00:49:39,029 have to think of now the interior of the 1257 00:49:45,410 --> 00:49:41,549 star rapidly rotating so it's really a 1258 00:49:47,420 --> 00:49:45,420 and a ball of gas that is rotating 1259 00:49:49,400 --> 00:49:47,430 extremely quickly and now it's going to 1260 00:49:51,380 --> 00:49:49,410 collapse in the usual way as a coral of 1261 00:49:53,420 --> 00:49:51,390 supernova would do so is speaking maybe 1262 00:49:56,690 --> 00:49:53,430 of kind of intermediate masters in in 1263 00:49:58,910 --> 00:49:56,700 general here and if the star was 1264 00:50:00,410 --> 00:49:58,920 internally rotating quick enough then 1265 00:50:02,690 --> 00:50:00,420 you can form an accretion disk around 1266 00:50:05,539 --> 00:50:02,700 this collapsing core so you're producing 1267 00:50:07,279 --> 00:50:05,549 a black hole in the star and while we're 1268 00:50:09,680 --> 00:50:07,289 producing this black hole the outside 1269 00:50:11,900 --> 00:50:09,690 exterior part of the star the envelope 1270 00:50:13,009 --> 00:50:11,910 they still have noticed that and you 1271 00:50:15,079 --> 00:50:13,019 form a black hole or with an accretion 1272 00:50:16,910 --> 00:50:15,089 disk and form a sufficient is you can 1273 00:50:18,620 --> 00:50:16,920 launch a jet and this jet can then 1274 00:50:19,339 --> 00:50:18,630 explore the whole star I think that's 1275 00:50:22,490 --> 00:50:19,349 pretty cool 1276 00:50:24,499 --> 00:50:22,500 that is very cool sounds a little bit 1277 00:50:26,480 --> 00:50:24,509 wildly coyote too because the black hole 1278 00:50:27,980 --> 00:50:26,490 arms but the rest of star doesn't notice 1279 00:50:29,329 --> 00:50:27,990 yet it's kind of like when the koala 1280 00:50:31,549 --> 00:50:29,339 coyote gets out and walks out on the 1281 00:50:33,049 --> 00:50:31,559 over though the cliff and doesn't notice 1282 00:50:36,859 --> 00:50:33,059 and then when he does known as he falls 1283 00:50:38,720 --> 00:50:36,869 so it sounds like that a lot okay it's 1284 00:50:40,700 --> 00:50:38,730 really cool okay well alright so we've 1285 00:50:43,099 --> 00:50:40,710 got core-collapse supernova we've got 1286 00:50:46,940 --> 00:50:43,109 pair-instability supernova long-duration 1287 00:50:48,529 --> 00:50:46,950 gamma-ray burst and we've already seen 1288 00:50:51,849 --> 00:50:48,539 that these things are rotating that we 1289 00:50:55,009 --> 00:50:51,859 have lots of binary components to it 1290 00:50:56,870 --> 00:50:55,019 what about what about binary black holes 1291 00:50:58,099 --> 00:50:56,880 would those get forms and Selma maybe 1292 00:51:04,080 --> 00:50:58,109 you could give us some comments on that 1293 00:51:09,730 --> 00:51:07,000 yeah so a couple of weeks ago of course 1294 00:51:13,450 --> 00:51:09,740 entire astronomy and physics was on its 1295 00:51:16,510 --> 00:51:13,460 head for the news of LIGO had found two 1296 00:51:19,120 --> 00:51:16,520 massive black holes massive 30 times as 1297 00:51:20,710 --> 00:51:19,130 massive at the Sun so we also he didn't 1298 00:51:22,630 --> 00:51:20,720 know that those are forming we had never 1299 00:51:24,100 --> 00:51:22,640 seen a 30 solar mass black hole we had 1300 00:51:27,820 --> 00:51:24,110 never seen a single black hole 1301 00:51:29,860 --> 00:51:27,830 we only know like boring black holes and 1302 00:51:32,200 --> 00:51:29,870 so we were extremely surprised they were 1303 00:51:34,480 --> 00:51:32,210 so massive and so it's two ideas how you 1304 00:51:36,820 --> 00:51:34,490 can make them and one involves a dense 1305 00:51:39,790 --> 00:51:36,830 star cluster something like r136 1306 00:51:42,010 --> 00:51:39,800 and the other idea involves a binary 1307 00:51:44,530 --> 00:51:42,020 system that has a special way of keeping 1308 00:51:47,020 --> 00:51:44,540 the stars together when they die and 1309 00:51:49,000 --> 00:51:47,030 make two black holes some some different 1310 00:51:50,920 --> 00:51:49,010 flavors do this and so now we're looking 1311 00:51:55,090 --> 00:51:50,930 at the star cluster we could do both 1312 00:51:56,170 --> 00:51:55,100 things in this one region right and so 1313 00:51:57,520 --> 00:51:56,180 it's very nice that the metallicity 1314 00:51:59,080 --> 00:51:57,530 talks a little bit about it that the 1315 00:52:01,840 --> 00:51:59,090 Middle East is a little bit lower so we 1316 00:52:04,660 --> 00:52:01,850 think that that helps for these stars to 1317 00:52:06,400 --> 00:52:04,670 not blow off to of too much mast and so 1318 00:52:08,920 --> 00:52:06,410 they actually can stay very massive and 1319 00:52:10,750 --> 00:52:08,930 maybe make pretty massive black holes so 1320 00:52:12,370 --> 00:52:10,760 maybe it was a cluster like this cluster 1321 00:52:15,400 --> 00:52:12,380 that made the two black holes that we 1322 00:52:18,520 --> 00:52:15,410 recently saw I mean I should say he 1323 00:52:20,770 --> 00:52:18,530 heard coalescing right it's the chirp I 1324 00:52:25,900 --> 00:52:20,780 don't know if you have seen the sound 1325 00:52:29,760 --> 00:52:25,910 movies they whoop yeah anyway so uh so 1326 00:52:32,020 --> 00:52:29,770 studies like this pole Crowder and his 1327 00:52:34,060 --> 00:52:32,030 expose dock and our all the 1328 00:52:35,770 --> 00:52:34,070 collaborators we're further examining 1329 00:52:37,150 --> 00:52:35,780 all the other stars in the star clusters 1330 00:52:38,680 --> 00:52:37,160 are we trying to understand better how 1331 00:52:40,420 --> 00:52:38,690 these stars live their life and 1332 00:52:42,490 --> 00:52:40,430 eventually as Fabien explained how they 1333 00:52:43,930 --> 00:52:42,500 die and what kind of black holes they 1334 00:52:45,550 --> 00:52:43,940 make and it's one of the big questions 1335 00:52:47,710 --> 00:52:45,560 we're trying to address here and Hubble 1336 00:52:49,690 --> 00:52:47,720 is has been amazing there to help out I 1337 00:52:51,400 --> 00:52:49,700 know it's it's it's just astonishing to 1338 00:52:52,870 --> 00:52:51,410 think about the idea that now we've got 1339 00:52:55,780 --> 00:52:52,880 the ability to detect gravitational 1340 00:52:57,970 --> 00:52:55,790 waves maybe this would be a sounds to me 1341 00:52:59,770 --> 00:52:57,980 like a pretty good target this this this 1342 00:53:02,320 --> 00:52:59,780 neighboring galaxies to take a look and 1343 00:53:05,230 --> 00:53:02,330 see what might come out of that most of 1344 00:53:07,630 --> 00:53:05,240 the stars are they still there in this 1345 00:53:09,730 --> 00:53:07,640 coming by that I mean have many is there 1346 00:53:12,160 --> 00:53:09,740 a way to know how many have died or 1347 00:53:13,780 --> 00:53:12,170 where we are in this whole evolution of 1348 00:53:14,800 --> 00:53:13,790 the star forming region so these stars 1349 00:53:18,130 --> 00:53:14,810 are still too young 1350 00:53:20,140 --> 00:53:18,140 we may be possibly one has made a black 1351 00:53:21,730 --> 00:53:20,150 hole already but we don't think so 1352 00:53:23,740 --> 00:53:21,740 it is this particularly since probably 1353 00:53:24,940 --> 00:53:23,750 too young and then as soon as you make 1354 00:53:27,100 --> 00:53:24,950 the black hole you still have to wait 1355 00:53:29,950 --> 00:53:27,110 for an extremely long time for the two 1356 00:53:31,300 --> 00:53:29,960 black holes to come together so they are 1357 00:53:33,100 --> 00:53:31,310 if you would have two black holes in a 1358 00:53:34,900 --> 00:53:33,110 binary it takes a long long time for 1359 00:53:36,790 --> 00:53:34,910 gravitational waves to slowly move them 1360 00:53:39,010 --> 00:53:36,800 together it would take Giga years and 1361 00:53:40,900 --> 00:53:39,020 then the last moment the gravitational 1362 00:53:43,090 --> 00:53:40,910 waves become very strong and that's when 1363 00:53:46,300 --> 00:53:43,100 we can listen teresting at the very end 1364 00:53:49,060 --> 00:53:46,310 I guess for this one we're not gonna we 1365 00:53:50,710 --> 00:53:49,070 got not gonna hear binary black hole 1366 00:53:52,480 --> 00:53:50,720 merger from this particular cluster but 1367 00:53:54,250 --> 00:53:52,490 we might hear from something from a 1368 00:53:56,560 --> 00:53:54,260 cluster that is like this one but that 1369 00:54:02,440 --> 00:53:56,570 is a bit further out in the universe and 1370 00:54:04,830 --> 00:54:02,450 it had time to wait so okay so here he 1371 00:54:07,630 --> 00:54:04,840 is a question from Karnak crux from 1372 00:54:09,880 --> 00:54:07,640 YouTube I wonder if James Webb will have 1373 00:54:12,520 --> 00:54:09,890 enough resolution to resolve the 1374 00:54:15,700 --> 00:54:12,530 population three first light stars and 1375 00:54:17,290 --> 00:54:15,710 the answer to that is yes it will and 1376 00:54:20,980 --> 00:54:17,300 I've talked to Massimo Steve Elia about 1377 00:54:23,110 --> 00:54:20,990 this a lot he's the JWST mission head at 1378 00:54:25,030 --> 00:54:23,120 the at the Institute and he was 1379 00:54:26,230 --> 00:54:25,040 explaining a lot about these stars and 1380 00:54:29,080 --> 00:54:26,240 what they're hoping to learn from James 1381 00:54:30,850 --> 00:54:29,090 Webb so the answer to that is yes and 1382 00:54:33,460 --> 00:54:30,860 they will hopefully teach us a lot about 1383 00:54:35,950 --> 00:54:33,470 stars like these but obviously a lot 1384 00:54:37,450 --> 00:54:35,960 less lower in metal content and probably 1385 00:54:38,580 --> 00:54:37,460 a lot smaller from the sounds of what 1386 00:54:42,520 --> 00:54:38,590 I'm hearing today 1387 00:54:44,590 --> 00:54:42,530 Barbara Kyle Cova is asking do you think 1388 00:54:47,170 --> 00:54:44,600 that if the vampire star consumes 1389 00:54:50,320 --> 00:54:47,180 another Stars mass does it get bigger 1390 00:54:53,230 --> 00:54:50,330 and if so when it confused astronomers 1391 00:54:56,260 --> 00:54:53,240 because when calculating its age because 1392 00:54:58,090 --> 00:54:56,270 it depends also on its size wants to 1393 00:55:00,640 --> 00:54:58,100 take that one yeah exactly 1394 00:55:03,280 --> 00:55:00,650 so yeah together with fabric we have 1395 00:55:05,230 --> 00:55:03,290 been writing papers on this so these 1396 00:55:07,630 --> 00:55:05,240 blue stragglers if they eat mass from 1397 00:55:10,000 --> 00:55:07,640 the other star we really like vampire 1398 00:55:12,280 --> 00:55:10,010 stars they kind of get new fuel from the 1399 00:55:14,680 --> 00:55:12,290 other star and that rejuvenates them it 1400 00:55:16,660 --> 00:55:14,690 makes them younger right and so if we 1401 00:55:19,690 --> 00:55:16,670 see these stars we would think they're 1402 00:55:21,220 --> 00:55:19,700 younger than they really are and so now 1403 00:55:23,200 --> 00:55:21,230 this whole clusters were young so it's a 1404 00:55:25,780 --> 00:55:23,210 bit hard to tell but these most massive 1405 00:55:28,120 --> 00:55:25,790 stars they're they're incredibly blue 1406 00:55:30,250 --> 00:55:28,130 and if they 1407 00:55:32,620 --> 00:55:30,260 be bit over we you would expect them to 1408 00:55:34,180 --> 00:55:32,630 be a little rather it's hard to tell for 1409 00:55:35,530 --> 00:55:34,190 this cluster but for clusters like this 1410 00:55:37,090 --> 00:55:35,540 we've seen that the most massive stars 1411 00:55:39,220 --> 00:55:37,100 are definitely younger than the other 1412 00:55:40,690 --> 00:55:39,230 stars and so if you would match the age 1413 00:55:42,370 --> 00:55:40,700 of that star cluster from the most 1414 00:55:43,240 --> 00:55:42,380 massive stars you act yeah you are 1415 00:55:44,950 --> 00:55:43,250 confused you 1416 00:55:48,280 --> 00:55:44,960 you think it's younger than it release 1417 00:55:50,020 --> 00:55:48,290 it's like there's a way to beat it it's 1418 00:55:51,640 --> 00:55:50,030 a facelift for the cluster yeah there's 1419 00:55:55,000 --> 00:55:51,650 many ways for you to pretend you're 1420 00:55:58,960 --> 00:55:55,010 younger but you know just for men and 1421 00:56:01,210 --> 00:55:58,970 your goatee might help - oh no I okay so 1422 00:56:01,830 --> 00:56:01,220 you look sophisticated in the House of 1423 00:56:04,960 --> 00:56:01,840 Lords 1424 00:56:09,550 --> 00:56:04,970 thank you okay well let's go - so while 1425 00:56:11,860 --> 00:56:09,560 I've got you here Scott what about 1426 00:56:15,580 --> 00:56:11,870 Twitter at all are we getting any other 1427 00:56:17,560 --> 00:56:15,590 Tweety files from the Tweety pies but we 1428 00:56:19,750 --> 00:56:17,570 are having lots of activity on on 1429 00:56:21,850 --> 00:56:19,760 Twitter especially as people just really 1430 00:56:26,170 --> 00:56:21,860 loving the the graphics that you guys 1431 00:56:28,060 --> 00:56:26,180 created from ESO the the images that 1432 00:56:31,870 --> 00:56:28,070 we've released from Hubble and the pie 1433 00:56:34,690 --> 00:56:31,880 chart was lovely as well yes ah yes so 1434 00:56:36,460 --> 00:56:34,700 that pie charts awesome and as well as 1435 00:56:38,410 --> 00:56:36,470 what I really loved and I'm seeing a lot 1436 00:56:40,450 --> 00:56:38,420 of conversation about is from the 1437 00:56:42,670 --> 00:56:40,460 comparison between the red dwarf the 1438 00:56:45,820 --> 00:56:42,680 yellow dwarf like our son a blue dwarf 1439 00:56:48,550 --> 00:56:45,830 and then just how much those are dwarfed 1440 00:56:49,630 --> 00:56:48,560 by our 136 oh that's like Paul calls 1441 00:56:51,250 --> 00:56:49,640 everything at dwarf I don't remember 1442 00:56:53,110 --> 00:56:51,260 calling I don't remember hearing a 1443 00:56:54,850 --> 00:56:53,120 yellow dwarf or a blue dwarf until I saw 1444 00:56:58,570 --> 00:56:54,860 that things because everything is dwarf 1445 00:57:00,760 --> 00:56:58,580 to that when that's what you're used to 1446 00:57:02,830 --> 00:57:00,770 working with I guess so alright you know 1447 00:57:07,210 --> 00:57:02,840 it is everything's tiny you know it's 1448 00:57:09,280 --> 00:57:07,220 all perspective okay well so what's so 1449 00:57:10,930 --> 00:57:09,290 what's next for you guys so you've got 1450 00:57:11,830 --> 00:57:10,940 these observations in are you going to 1451 00:57:14,200 --> 00:57:11,840 be follow doing some follow-up 1452 00:57:16,000 --> 00:57:14,210 observations with this cluster are you 1453 00:57:17,680 --> 00:57:16,010 looking at other clusters and I'll have 1454 00:57:19,390 --> 00:57:17,690 maybe maybe Fabian you can give us some 1455 00:57:21,910 --> 00:57:19,400 idea what's what's next for you guys I 1456 00:57:25,510 --> 00:57:21,920 would probably like to pass a credit 1457 00:57:27,220 --> 00:57:25,520 report because he's still sitting about 1458 00:57:29,530 --> 00:57:27,230 this particular cluster and even even 1459 00:57:33,700 --> 00:57:29,540 more so good so once you tell us what's 1460 00:57:35,440 --> 00:57:33,710 next for yes published the study of your 1461 00:57:36,700 --> 00:57:35,450 father Neil G violet and we're now 1462 00:57:38,350 --> 00:57:36,710 working through some optical 1463 00:57:41,140 --> 00:57:38,360 observations we've taken with Hubble 1464 00:57:41,440 --> 00:57:41,150 face and looking at the looking looking 1465 00:57:43,839 --> 00:57:41,450 for 1466 00:57:46,270 --> 00:57:43,849 is amongst the stars in the cluster 1467 00:57:48,040 --> 00:57:46,280 we're looking for how fast the stars are 1468 00:57:50,200 --> 00:57:48,050 rotating now give us a clue as to 1469 00:57:55,630 --> 00:57:50,210 whether they they've been spun up it's 1470 00:57:57,190 --> 00:57:55,640 really spam pyre mass exchange and 1471 00:57:59,890 --> 00:57:57,200 actually with with summer we're also 1472 00:58:02,500 --> 00:57:59,900 looking at with huh ball in ships this 1473 00:58:04,060 --> 00:58:02,510 has a exquisite angular resolution to be 1474 00:58:05,770 --> 00:58:04,070 able to resolve these stars we should 1475 00:58:07,210 --> 00:58:05,780 look very close together but there's 1476 00:58:10,060 --> 00:58:07,220 actually other instrument on Hubble 1477 00:58:13,210 --> 00:58:10,070 called fgs and that can actually go a 1478 00:58:15,490 --> 00:58:13,220 factor of factor of 10 better in angular 1479 00:58:17,550 --> 00:58:15,500 resolution so with Selma and my postdoc 1480 00:58:20,800 --> 00:58:17,560 we're looking at trying to look for 1481 00:58:23,319 --> 00:58:20,810 faint companions it's a much closer 1482 00:58:26,680 --> 00:58:23,329 separation than we can do with the kind 1483 00:58:29,650 --> 00:58:26,690 of conventional imaging approach so the 1484 00:58:32,950 --> 00:58:29,660 supercar loop the thing is there isn't 1485 00:58:34,710 --> 00:58:32,960 anything quite as impressive or more 1486 00:58:37,359 --> 00:58:34,720 impressive than our 36 1487 00:58:39,940 --> 00:58:37,369 within our galaxies this nothing is 1488 00:58:42,579 --> 00:58:39,950 impressive in Andromeda or in the 1489 00:58:45,520 --> 00:58:42,589 triangular member 3 and so you've got to 1490 00:58:47,170 --> 00:58:45,530 go quite a lot further away to find more 1491 00:58:49,990 --> 00:58:47,180 impressive star clusters than this one 1492 00:58:52,569 --> 00:58:50,000 and so really I think that the next for 1493 00:58:54,250 --> 00:58:52,579 the next in a while is to really get the 1494 00:58:58,210 --> 00:58:54,260 most out of this cluster to look for 1495 00:59:00,190 --> 00:58:58,220 look for binaries look for to figure 1496 00:59:03,099 --> 00:59:00,200 this as much as we can it's really great 1497 00:59:04,870 --> 00:59:03,109 it's such an amazing stellar nursery is 1498 00:59:07,510 --> 00:59:04,880 so close by for you to be able to study 1499 00:59:08,740 --> 00:59:07,520 that's really good so cool all right 1500 00:59:10,480 --> 00:59:08,750 well we'll look forward to hearing more 1501 00:59:14,079 --> 00:59:10,490 from you guys in your press releases and 1502 00:59:17,079 --> 00:59:14,089 your paper so thank you guys for joining 1503 00:59:18,819 --> 00:59:17,089 us so on behalf of Paul Crowther baby 1504 00:59:20,140 --> 00:59:18,829 and Schneider and so I'm gonna mink I 1505 00:59:21,849 --> 00:59:20,150 want to thank you and thank my guests 1506 00:59:24,760 --> 00:59:21,859 for showing up taking time out of their 1507 00:59:26,680 --> 00:59:24,770 day to explain there's awesome science 1508 00:59:29,050 --> 00:59:26,690 and the going on in the Large Magellanic 1509 00:59:32,290 --> 00:59:29,060 Cloud with the youngest or some of the 1510 00:59:34,780 --> 00:59:32,300 most massive stars in the known universe 1511 00:59:36,520 --> 00:59:34,790 writing next door right over there next 1512 00:59:38,950 --> 00:59:36,530 to Scotts house so that's where I don't 1513 00:59:42,370 --> 00:59:38,960 from my house if you know it's kind of a 1514 00:59:45,130 --> 00:59:42,380 big deal out here yeah I do want to 1515 00:59:46,510 --> 00:59:45,140 learn a lot more questions out there I'm 1516 00:59:48,309 --> 00:59:46,520 sorry we have many and we'll answer them 1517 00:59:50,410 --> 00:59:48,319 but there Ben this is just a fascinating 1518 00:59:52,600 --> 00:59:50,420 topic so well we'll try to do is try to 1519 00:59:54,610 --> 00:59:52,610 hit some of those on Twitter later on 1520 00:59:57,430 --> 00:59:54,620 or in the comments later on YouTube and 1521 00:59:59,200 --> 00:59:57,440 Facebook alright that's it and on behalf 1522 01:00:00,400 --> 00:59:59,210 of Karol Christian I will and Scott 1523 01:00:02,170 --> 01:00:00,410 Lewis I want to thank you all for 1524 01:00:04,750 --> 01:00:02,180 watching we'll be back next week same 1525 01:00:06,850 --> 01:00:04,760 time Thursday 3:00 p.m. Eastern I don't 1526 01:00:09,700 --> 01:00:06,860 know what the topic is because Carol 1527 01:00:12,460 --> 01:00:09,710 does that and so she'll tell us what you 1528 01:00:13,930 --> 01:00:12,470 drink what we talking about but we will 1529 01:00:15,370 --> 01:00:13,940 be back so hope you guys can tune in if 1530 01:00:16,450 --> 01:00:15,380 you have not subscribed to Hubble site 1531 01:00:18,070 --> 01:00:16,460 channel please do that 1532 01:00:20,110 --> 01:00:18,080 by clicking on the little subscribe 1533 01:00:23,350 --> 01:00:20,120 button on the channel page also follow 1534 01:00:26,650 --> 01:00:23,360 us on twitter at hubble telescope and as