1 00:02:45,209 --> 00:02:43,619 good afternoon welcome to Goddard Space 2 00:02:47,940 --> 00:02:45,219 Flight Center and todays space astronomy 3 00:02:49,410 --> 00:02:47,950 update where we will have today some of 4 00:02:51,270 --> 00:02:49,420 the most dramatic pictures yet from the 5 00:02:54,030 --> 00:02:51,280 Hubble Space Telescope and here to tell 6 00:02:56,489 --> 00:02:54,040 us about it and the findings is our 7 00:02:58,379 --> 00:02:56,499 distinguished panel and our host Steve 8 00:03:00,360 --> 00:02:58,389 marant an astronomer from Goddard Space 9 00:03:01,920 --> 00:03:00,370 Flight Center Steve thanks Don and 10 00:03:04,559 --> 00:03:01,930 welcome to space astronomy update 11 00:03:05,550 --> 00:03:04,569 everybody originating today from Goddard 12 00:03:08,490 --> 00:03:05,560 Space Flight Center in Greenbelt 13 00:03:11,819 --> 00:03:08,500 Maryland and with us today to discuss 14 00:03:15,690 --> 00:03:11,829 the birth pangs of stars like the Sun 15 00:03:18,119 --> 00:03:15,700 and its solar system are three experts 16 00:03:19,640 --> 00:03:18,129 have been investigating these objects 17 00:03:22,949 --> 00:03:19,650 with the Hubble Space Telescope 18 00:03:25,170 --> 00:03:22,959 professor Jeff Hester from the arizona 19 00:03:27,689 --> 00:03:25,180 state university in tempe an 20 00:03:29,789 --> 00:03:27,699 investigator of nebulae of some 21 00:03:31,920 --> 00:03:29,799 distinction and a member of the original 22 00:03:34,470 --> 00:03:31,930 wide field and planetary camera team for 23 00:03:36,809 --> 00:03:34,480 the Hubble Space Telescope and also 24 00:03:39,959 --> 00:03:36,819 we're glad to have a young postdoctoral 25 00:03:42,300 --> 00:03:39,969 researcher dr. John Morse of the Space 26 00:03:44,789 --> 00:03:42,310 Telescope Science Institute in Baltimore 27 00:03:46,920 --> 00:03:44,799 did his PhD on these objects at 28 00:03:49,259 --> 00:03:46,930 University of North Carolina a Harvard 29 00:03:51,330 --> 00:03:49,269 graduate and welcome back to space 30 00:03:53,309 --> 00:03:51,340 astronomy update one of the optics 31 00:03:54,960 --> 00:03:53,319 experts of the Hubble Space Telescope a 32 00:03:58,229 --> 00:03:54,970 member of the wide field and planetary 33 00:03:59,819 --> 00:03:58,239 camera 2 team from the European Space 34 00:04:02,580 --> 00:03:59,829 Agency in Space Telescope Science 35 00:04:06,199 --> 00:04:02,590 Institute Chris burrows dr. Chris 36 00:04:08,610 --> 00:04:06,209 burrows and our independent panelist 37 00:04:11,729 --> 00:04:08,620 chairman of the department of astronomy 38 00:04:13,949 --> 00:04:11,739 University of Washington in Seattle dr. 39 00:04:15,990 --> 00:04:13,959 Bruce margon who is the chairman of the 40 00:04:18,300 --> 00:04:16,000 board of the Astrophysical research 41 00:04:20,310 --> 00:04:18,310 consortium and just appointed as the 42 00:04:22,350 --> 00:04:20,320 next chairman of the board of the 43 00:04:25,200 --> 00:04:22,360 Association of universities for research 44 00:04:26,790 --> 00:04:25,210 in astronomy head of two boards but he 45 00:04:28,740 --> 00:04:26,800 won't leave anyone bored because he's 46 00:04:31,290 --> 00:04:28,750 one of the brilliant communicators of 47 00:04:33,209 --> 00:04:31,300 the astronomical research now we're 48 00:04:36,029 --> 00:04:33,219 talking about her big harrow objects and 49 00:04:37,909 --> 00:04:36,039 Jeff Hester what are they and what have 50 00:04:40,260 --> 00:04:37,919 you seen with the Hubble telescope well 51 00:04:41,879 --> 00:04:40,270 I'll back up a little bit and first 52 00:04:44,149 --> 00:04:41,889 start talking about why it is that star 53 00:04:47,120 --> 00:04:44,159 formation is such a fascinating question 54 00:04:49,080 --> 00:04:47,130 when we look at stars forming 55 00:04:51,390 --> 00:04:49,090 astronomers never get a chance to 56 00:04:53,610 --> 00:04:51,400 actually see stars for me but what we 57 00:04:54,930 --> 00:04:53,620 can do instead is look out at different 58 00:04:56,250 --> 00:04:54,940 objects and catch them 59 00:04:59,190 --> 00:04:56,260 different stages in the formation 60 00:05:01,620 --> 00:04:59,200 process and then use what we know with 61 00:05:03,450 --> 00:05:01,630 physics and of our local environment to 62 00:05:05,280 --> 00:05:03,460 put those together into a story which is 63 00:05:07,680 --> 00:05:05,290 becoming a remarkably clean story 64 00:05:09,450 --> 00:05:07,690 actually and this is exciting because 65 00:05:11,760 --> 00:05:09,460 really what we're seeing here is what 66 00:05:13,830 --> 00:05:11,770 happened five billion years ago when our 67 00:05:16,170 --> 00:05:13,840 own son and our own solar system came 68 00:05:17,760 --> 00:05:16,180 into being and so when we look at what 69 00:05:19,770 --> 00:05:17,770 we're going to be looking at today it's 70 00:05:22,410 --> 00:05:19,780 a bit of a time machine that lets us see 71 00:05:24,960 --> 00:05:22,420 into our own history and some of the why 72 00:05:27,620 --> 00:05:24,970 behind our own existence we could look 73 00:05:30,270 --> 00:05:27,630 at the first graphic a very important 74 00:05:33,210 --> 00:05:30,280 piece of this story was discovered in 75 00:05:35,100 --> 00:05:33,220 the 1950s by two astronomers by the name 76 00:05:38,850 --> 00:05:35,110 of George her big and Guillermo hello 77 00:05:41,670 --> 00:05:38,860 and what they found were Jets of glowing 78 00:05:44,310 --> 00:05:41,680 gas such as the jet here and the jet 79 00:05:47,010 --> 00:05:44,320 here clumps of glowing gas rather moving 80 00:05:49,470 --> 00:05:47,020 rapidly through space but we now 81 00:05:51,330 --> 00:05:49,480 understand is happening is that right 82 00:05:53,610 --> 00:05:51,340 about where the cross is now there's a 83 00:05:56,490 --> 00:05:53,620 brand new star that's forming material 84 00:05:59,190 --> 00:05:56,500 is flowing away from that star in two 85 00:06:01,080 --> 00:05:59,200 Jet's one in this direction and one in 86 00:06:03,870 --> 00:06:01,090 this direction it's called a bipolar 87 00:06:06,450 --> 00:06:03,880 outflow that material is streaming away 88 00:06:08,909 --> 00:06:06,460 from that forming star and then up in 89 00:06:10,920 --> 00:06:08,919 this area and down in this area it's 90 00:06:13,740 --> 00:06:10,930 running into ambient material the 91 00:06:15,540 --> 00:06:13,750 material that was around that star this 92 00:06:18,180 --> 00:06:15,550 is a Space Telescope picture of an 93 00:06:19,710 --> 00:06:18,190 object called h81 to which is one of 94 00:06:22,740 --> 00:06:19,720 four different objects that we're going 95 00:06:23,880 --> 00:06:22,750 to see images of today a nice thing 96 00:06:25,260 --> 00:06:23,890 about what we're going to see today 97 00:06:27,240 --> 00:06:25,270 we're going to see images of four 98 00:06:29,040 --> 00:06:27,250 separate objects and yet the story 99 00:06:31,980 --> 00:06:29,050 that's being told in those four separate 100 00:06:33,659 --> 00:06:31,990 objects is a common story you put it all 101 00:06:35,880 --> 00:06:33,669 together and you start to get a clear 102 00:06:38,190 --> 00:06:35,890 picture that answers some fundamental 103 00:06:40,710 --> 00:06:38,200 questions about how it is that stars 104 00:06:42,270 --> 00:06:40,720 form for example we're going to see some 105 00:06:45,300 --> 00:06:42,280 data that shows us the immediate 106 00:06:47,340 --> 00:06:45,310 environment around a forming star the 107 00:06:49,470 --> 00:06:47,350 things that might lead to solar systems 108 00:06:51,570 --> 00:06:49,480 and such as that we're going to see new 109 00:06:53,550 --> 00:06:51,580 information that tells us about the 110 00:06:55,800 --> 00:06:53,560 material flowing away from those stars 111 00:06:58,950 --> 00:06:55,810 and in particular tells us that that 112 00:07:00,750 --> 00:06:58,960 material brings with it the history of 113 00:07:03,150 --> 00:07:00,760 what was happening with the star itself 114 00:07:05,070 --> 00:07:03,160 and finally we're going to see a story 115 00:07:06,990 --> 00:07:05,080 about how that material goes out and 116 00:07:08,800 --> 00:07:07,000 interacts with the surroundings of the 117 00:07:10,690 --> 00:07:08,810 star which might be an 118 00:07:13,420 --> 00:07:10,700 piece of answering the question of what 119 00:07:16,210 --> 00:07:13,430 makes stars the size that they are if I 120 00:07:19,240 --> 00:07:16,220 could have the next graphic this is an 121 00:07:20,830 --> 00:07:19,250 object called HH 34 and this is a 122 00:07:22,990 --> 00:07:20,840 different object from the last one that 123 00:07:25,960 --> 00:07:23,000 we showed you and what you see here 124 00:07:28,150 --> 00:07:25,970 again is right down at about this 125 00:07:30,970 --> 00:07:28,160 location right at the tip of that little 126 00:07:33,610 --> 00:07:30,980 arrow shape is where the star itself is 127 00:07:36,640 --> 00:07:33,620 the light that you see right around that 128 00:07:38,620 --> 00:07:36,650 is light that's being reflected from the 129 00:07:41,650 --> 00:07:38,630 cloud and the disk from which that star 130 00:07:45,640 --> 00:07:41,660 is forming coming out away from that 131 00:07:47,290 --> 00:07:45,650 star is an exceedingly thin jet and one 132 00:07:49,659 --> 00:07:47,300 of the new results that will be talking 133 00:07:52,330 --> 00:07:49,669 about today is the fact that that jet is 134 00:07:53,710 --> 00:07:52,340 so very very thin right at its tip that 135 00:07:56,770 --> 00:07:53,720 tells us it's coming from the star 136 00:07:58,780 --> 00:07:56,780 itself almost that material then comes 137 00:08:01,750 --> 00:07:58,790 streaming out through interstellar space 138 00:08:04,659 --> 00:08:01,760 and if you see each of these knots along 139 00:08:07,270 --> 00:08:04,669 here they sort of look like a train of 140 00:08:09,219 --> 00:08:07,280 motorboats each of which has its own 141 00:08:11,680 --> 00:08:09,229 little bow wave and that's a very 142 00:08:13,360 --> 00:08:11,690 exciting new result when astronomers 143 00:08:16,060 --> 00:08:13,370 first looked at these jets they 144 00:08:17,770 --> 00:08:16,070 understood that they were clumpy but 145 00:08:20,529 --> 00:08:17,780 many astronomers believe that those 146 00:08:22,960 --> 00:08:20,539 clumps were in fact due to a smooth flow 147 00:08:25,600 --> 00:08:22,970 in the jet that had some sort of funny 148 00:08:27,010 --> 00:08:25,610 internal structure in it for those of 149 00:08:28,240 --> 00:08:27,020 you who've watched a space shuttle take 150 00:08:30,100 --> 00:08:28,250 off you might notice that there are 151 00:08:32,230 --> 00:08:30,110 little diamond-shaped features behind 152 00:08:34,120 --> 00:08:32,240 the shuttle main engines we now know 153 00:08:36,520 --> 00:08:34,130 that's not what's going on in these jets 154 00:08:38,500 --> 00:08:36,530 that in fact each one of these knots is 155 00:08:40,839 --> 00:08:38,510 a separate little puff of material 156 00:08:43,060 --> 00:08:40,849 bursts of material that came off of the 157 00:08:45,400 --> 00:08:43,070 forming star and we can look at those 158 00:08:49,630 --> 00:08:45,410 bursts and find out not only about the 159 00:08:53,590 --> 00:08:49,640 jet itself but about the source finally 160 00:08:56,500 --> 00:08:53,600 to to close up a few opening thoughts we 161 00:08:58,270 --> 00:08:56,510 see jets in these forming stars but the 162 00:09:00,220 --> 00:08:58,280 jets that we see in these forming stars 163 00:09:02,130 --> 00:09:00,230 are also very similar to the jets that 164 00:09:04,300 --> 00:09:02,140 astronomers see when they study 165 00:09:07,210 --> 00:09:04,310 quasi-stellar objects when they study 166 00:09:09,850 --> 00:09:07,220 radio galaxies when they study jets that 167 00:09:11,650 --> 00:09:09,860 cover millions of light-years of 168 00:09:13,690 --> 00:09:11,660 interstellar space and when they talk 169 00:09:16,300 --> 00:09:13,700 about massive black holes at the Centers 170 00:09:18,910 --> 00:09:16,310 of galaxies here we're looking at the 171 00:09:20,890 --> 00:09:18,920 very same types of phenomena that now 172 00:09:22,289 --> 00:09:20,900 close by where we can study them in more 173 00:09:28,089 --> 00:09:22,299 d 174 00:09:30,400 --> 00:09:28,099 Morris what have you seen of these 175 00:09:32,829 --> 00:09:30,410 objects with bubble well aside from 176 00:09:35,650 --> 00:09:32,839 investigating the origin of the Jets we 177 00:09:37,509 --> 00:09:35,660 might also ask how these Jets interact 178 00:09:40,139 --> 00:09:37,519 with their environments and how 179 00:09:44,019 --> 00:09:40,149 important they an impact they may have 180 00:09:45,999 --> 00:09:44,029 these new hubble space telescope images 181 00:09:48,429 --> 00:09:46,009 show us for the first time the details 182 00:09:51,909 --> 00:09:48,439 of the interactions between the Jets and 183 00:09:55,479 --> 00:09:51,919 the interstellar gas first of all the 184 00:09:57,729 --> 00:09:55,489 Jets travel at very high speeds hundreds 185 00:10:00,069 --> 00:09:57,739 of kilometers per second and shockwaves 186 00:10:01,929 --> 00:10:00,079 form along the flow where it interacts 187 00:10:04,889 --> 00:10:01,939 with the interstellar gas causing the 188 00:10:08,439 --> 00:10:04,899 jet and that interstellar gas to glow 189 00:10:12,339 --> 00:10:08,449 the shockwaves sweep away material from 190 00:10:14,409 --> 00:10:12,349 the protostar and may in fact restrict 191 00:10:18,129 --> 00:10:14,419 how much material is available to build 192 00:10:20,769 --> 00:10:18,139 the star secondly the Jets propagate for 193 00:10:24,609 --> 00:10:20,779 very large distances at least several 194 00:10:26,889 --> 00:10:24,619 yard light years in some cases they 195 00:10:29,319 --> 00:10:26,899 deposit considerable energy into the gas 196 00:10:33,279 --> 00:10:29,329 clouds which are forming stars and so 197 00:10:34,869 --> 00:10:33,289 somewhat ironically if you have a gas 198 00:10:37,989 --> 00:10:34,879 cloud which is sitting there forming 199 00:10:41,469 --> 00:10:37,999 stars the actual process of star 200 00:10:44,529 --> 00:10:41,479 formation may wind up destroying the gas 201 00:10:47,679 --> 00:10:44,539 cloud for example let's look at the HH 202 00:10:52,329 --> 00:10:47,689 47 system if we can bring up the first 203 00:10:54,909 --> 00:10:52,339 graphic this is a ground-based image 204 00:10:58,389 --> 00:10:54,919 taken by bo raipur at the european 205 00:11:00,609 --> 00:10:58,399 southern observatory this is the outline 206 00:11:02,619 --> 00:11:00,619 of the cloud here and there's a single 207 00:11:04,960 --> 00:11:02,629 star which is forming down in the cloud 208 00:11:08,889 --> 00:11:04,970 the star is located about right here 209 00:11:12,429 --> 00:11:08,899 it's invisible in the optical but we can 210 00:11:14,799 --> 00:11:12,439 detect it in the infrared this jet is 211 00:11:16,989 --> 00:11:14,809 driving two Jet's one to the Northeast 212 00:11:18,999 --> 00:11:16,999 which is up here which is slightly 213 00:11:20,710 --> 00:11:19,009 inclined towards us so it comes out of 214 00:11:23,889 --> 00:11:20,720 the cloud and we can see it the other 215 00:11:28,300 --> 00:11:23,899 jet we can faintly see right here and it 216 00:11:37,530 --> 00:11:32,260 mawlid zoom in on the details that the 217 00:11:42,850 --> 00:11:40,420 first of all we see that the jet has 218 00:11:44,829 --> 00:11:42,860 carved a hole in the gas cloud remember 219 00:11:47,170 --> 00:11:44,839 the stars about right here and this jet 220 00:11:49,360 --> 00:11:47,180 is speeding off to the northeast 221 00:11:52,090 --> 00:11:49,370 direction here these white filaments are 222 00:11:54,190 --> 00:11:52,100 the walls of the cavity and it's just 223 00:11:55,840 --> 00:11:54,200 reflecting light from the star which is 224 00:11:59,440 --> 00:11:55,850 here which is shining through the hole 225 00:12:03,670 --> 00:11:59,450 carved out by the Jets the real news in 226 00:12:06,490 --> 00:12:03,680 this story is that we can see these thin 227 00:12:09,100 --> 00:12:06,500 shox structures along the edges of the 228 00:12:11,290 --> 00:12:09,110 jet highlighted in blue green here 229 00:12:13,240 --> 00:12:11,300 there's a series of them associated with 230 00:12:16,780 --> 00:12:13,250 these knots and there's a big one up 231 00:12:18,820 --> 00:12:16,790 here associated with the bow wave now 232 00:12:21,430 --> 00:12:18,830 these thin structures had never been 233 00:12:22,780 --> 00:12:21,440 seen before in exquisite detail that 234 00:12:26,260 --> 00:12:22,790 we're seeing here and this is the first 235 00:12:29,040 --> 00:12:26,270 time we've been able to tell how the jet 236 00:12:35,829 --> 00:12:29,050 will transfer momentum to the gas cloud 237 00:12:39,220 --> 00:12:35,839 okay Thank You Johnny Chris burrows you 238 00:12:42,280 --> 00:12:39,230 were with us last when we discover these 239 00:12:44,950 --> 00:12:42,290 or obtain a beautiful images of three 240 00:12:47,800 --> 00:12:44,960 rings around supernova 1987a want to 241 00:12:50,110 --> 00:12:47,810 know what you have to top it well in 242 00:12:54,310 --> 00:12:50,120 some ways this desktop it what we see 243 00:12:56,740 --> 00:12:54,320 with Hubble now is an image of star in 244 00:12:58,329 --> 00:12:56,750 the closest star forming region so here 245 00:13:00,250 --> 00:12:58,339 we have a unique opportunity this is the 246 00:13:01,660 --> 00:13:00,260 closest star forming region to us and 247 00:13:04,210 --> 00:13:01,670 we're looking at it with the most 248 00:13:10,060 --> 00:13:04,220 powerful telescope available to humans 249 00:13:11,890 --> 00:13:10,070 and what we see is is around the star we 250 00:13:14,590 --> 00:13:11,900 see the disk of material that's falling 251 00:13:17,079 --> 00:13:14,600 in to form the start and we see the jet 252 00:13:21,010 --> 00:13:17,089 being formed this is the image that 253 00:13:22,900 --> 00:13:21,020 we've obtained and you can see this disc 254 00:13:24,430 --> 00:13:22,910 here this is the top surface of the disc 255 00:13:25,660 --> 00:13:24,440 the back of the disc and this is the 256 00:13:27,579 --> 00:13:25,670 front of the disc these are both being 257 00:13:29,680 --> 00:13:27,589 lit up by the star that's forming in the 258 00:13:31,660 --> 00:13:29,690 middle here now we can't see the star at 259 00:13:34,470 --> 00:13:31,670 all because it's obscured behind the 260 00:13:37,780 --> 00:13:34,480 disc itself it's there's a very dense 261 00:13:39,850 --> 00:13:37,790 band of dust between us and the star and 262 00:13:41,860 --> 00:13:39,860 in fact only one in a hundred billion 263 00:13:43,900 --> 00:13:41,870 billion photons that come from that 264 00:13:46,090 --> 00:13:43,910 star actually make it back out to us 265 00:13:47,620 --> 00:13:46,100 directly but quite a few as you can see 266 00:13:49,540 --> 00:13:47,630 a reflective from the disc so you can 267 00:13:52,180 --> 00:13:49,550 see the shape of the disc and we're able 268 00:13:54,460 --> 00:13:52,190 to quantitatively model it then we're 269 00:13:56,920 --> 00:13:54,470 also able to see the jet as it comes out 270 00:13:58,930 --> 00:13:56,930 from the star and it's as the disc 271 00:14:02,019 --> 00:13:58,940 collapse on collapses to form the star 272 00:14:03,640 --> 00:14:02,029 it's super heated and the jet is 273 00:14:06,700 --> 00:14:03,650 material that's escaping and the only 274 00:14:09,700 --> 00:14:06,710 free path perpendicular to the disk gets 275 00:14:12,070 --> 00:14:09,710 jetted out in both directions and we're 276 00:14:13,810 --> 00:14:12,080 able to see it as a very fine stream 277 00:14:15,760 --> 00:14:13,820 coming right from the star it's 278 00:14:18,280 --> 00:14:15,770 unresolved even by hubble clothes into 279 00:14:20,410 --> 00:14:18,290 the star which means it's got the scales 280 00:14:23,590 --> 00:14:20,420 of less than the size of our solar 281 00:14:25,540 --> 00:14:23,600 system our solar system itself would fit 282 00:14:27,880 --> 00:14:25,550 in this image at about that size there 283 00:14:30,070 --> 00:14:27,890 across there so you can see that we're 284 00:14:32,410 --> 00:14:30,080 seeing now on the scale of our own solar 285 00:14:35,050 --> 00:14:32,420 system a star in the form in the process 286 00:14:36,970 --> 00:14:35,060 of forming and indeed when this star has 287 00:14:40,570 --> 00:14:36,980 formed the material that is left behind 288 00:14:45,310 --> 00:14:40,580 in the disk could well eventually form 289 00:14:47,800 --> 00:14:45,320 planets so okay Thank You Kris and Bruce 290 00:14:50,050 --> 00:14:47,810 marg on these are amazing pictures of 291 00:14:52,420 --> 00:14:50,060 jets and all I'm sure most people 292 00:14:55,150 --> 00:14:52,430 haven't thought of phenomena like this 293 00:14:56,800 --> 00:14:55,160 very much in there people read about how 294 00:14:59,290 --> 00:14:56,810 the Sun might have formed it stars from 295 00:15:01,810 --> 00:14:59,300 how does this fit with our solar system 296 00:15:03,940 --> 00:15:01,820 good got into being well you're right 297 00:15:06,670 --> 00:15:03,950 Steve that when people think about these 298 00:15:10,269 --> 00:15:06,680 narrowly focused jets and astronomy they 299 00:15:12,070 --> 00:15:10,279 normally think about a larger scale far 300 00:15:13,870 --> 00:15:12,080 more violent events in astronomy like 301 00:15:16,090 --> 00:15:13,880 quasi-stellar objects that are ejecting 302 00:15:18,100 --> 00:15:16,100 huge amounts of material over scales and 303 00:15:20,350 --> 00:15:18,110 millions of light years here we're 304 00:15:22,150 --> 00:15:20,360 talking about a far more common 305 00:15:24,850 --> 00:15:22,160 phenomenon indeed a phenomena every star 306 00:15:27,519 --> 00:15:24,860 has to undergo namely collapsing from a 307 00:15:30,910 --> 00:15:27,529 diffuse cloud to become a star and yet 308 00:15:33,190 --> 00:15:30,920 we see that these Jets still occur and 309 00:15:35,410 --> 00:15:33,200 they occur remarkably even though the 310 00:15:37,240 --> 00:15:35,420 scale is far far smaller with the same 311 00:15:41,800 --> 00:15:37,250 very very fine pointing in collimation 312 00:15:43,480 --> 00:15:41,810 and perhaps most remarkably of all we 313 00:15:47,410 --> 00:15:43,490 see these accretion disks these 314 00:15:50,470 --> 00:15:47,420 flattened pancakes of gas that expel 315 00:15:52,990 --> 00:15:50,480 these Jets now the most remarkable thing 316 00:15:54,550 --> 00:15:53,000 that I've seen thus far is this very 317 00:15:55,689 --> 00:15:54,560 most recent image that Christian shows 318 00:16:00,269 --> 00:15:55,699 maybe we could put it back up 319 00:16:04,509 --> 00:16:00,279 and if I were asked to draw on a napkin 320 00:16:07,030 --> 00:16:04,519 for a student a disk of gas that is 321 00:16:09,159 --> 00:16:07,040 falling on to something and some jets 322 00:16:10,869 --> 00:16:09,169 that were then expelled out this is 323 00:16:13,239 --> 00:16:10,879 exactly the drawing that I would make 324 00:16:15,579 --> 00:16:13,249 but this is not a drawing this is a 325 00:16:17,409 --> 00:16:15,589 picture this is an image obtained by the 326 00:16:19,869 --> 00:16:17,419 Hubble Space Telescope of an accretion 327 00:16:22,449 --> 00:16:19,879 disk accretion is a fundamental property 328 00:16:24,789 --> 00:16:22,459 in astronomy the water can't fall right 329 00:16:26,650 --> 00:16:24,799 down the bathtub drain the water has to 330 00:16:29,259 --> 00:16:26,660 swirl around first no matter what the 331 00:16:31,059 --> 00:16:29,269 environment in astronomy is the gas 332 00:16:33,189 --> 00:16:31,069 can't fall right on to something that's 333 00:16:35,199 --> 00:16:33,199 to swirl around for us to shed its spin 334 00:16:36,970 --> 00:16:35,209 times to shut its angular momentum so 335 00:16:38,499 --> 00:16:36,980 everyone is always said these disks must 336 00:16:40,929 --> 00:16:38,509 form and you draw this little cartoon 337 00:16:42,999 --> 00:16:40,939 but here we actually have an image of it 338 00:16:44,590 --> 00:16:43,009 this is really in my mind the picture 339 00:16:46,900 --> 00:16:44,600 that's worth a thousand words because 340 00:16:48,819 --> 00:16:46,910 this object is close enough that we can 341 00:16:51,129 --> 00:16:48,829 actually photograph this accretion disk 342 00:16:54,639 --> 00:16:51,139 did we not see a year or two ago from 343 00:16:58,030 --> 00:16:54,649 Hubble and this very program some dark 344 00:16:59,590 --> 00:16:58,040 disk in the galaxy NGC 4261 or there 345 00:17:01,629 --> 00:16:59,600 have been when object or another there 346 00:17:04,419 --> 00:17:01,639 have been previous Hubble images of 347 00:17:06,610 --> 00:17:04,429 active galaxies like NGC 4261 and 348 00:17:10,289 --> 00:17:06,620 another one is Messier 87 where the 349 00:17:13,990 --> 00:17:10,299 image shows a large donate donut shape 350 00:17:15,879 --> 00:17:14,000 structure of gas and dust but those are 351 00:17:19,480 --> 00:17:15,889 not accretion disks those are sort of 352 00:17:22,419 --> 00:17:19,490 the reservoirs of gas on a much larger 353 00:17:24,970 --> 00:17:22,429 spatial scale waiting their turn to fall 354 00:17:27,309 --> 00:17:24,980 in and in those external galaxies the 355 00:17:30,519 --> 00:17:27,319 actual accretion disk is much much too 356 00:17:31,779 --> 00:17:30,529 small to be seen because as both Chris 357 00:17:32,919 --> 00:17:31,789 and Jeff have indicated we're talking 358 00:17:35,769 --> 00:17:32,929 about structures about the size of our 359 00:17:38,529 --> 00:17:35,779 solar system here this object is close 360 00:17:40,990 --> 00:17:38,539 enough and Hubble's angular resolution 361 00:17:43,450 --> 00:17:41,000 ability to take sharp images is fine 362 00:17:46,779 --> 00:17:43,460 enough that we can actually see the 363 00:17:48,610 --> 00:17:46,789 pancake itself not the worst 830 picture 364 00:17:50,590 --> 00:17:48,620 is the first real picture of an 365 00:17:52,269 --> 00:17:50,600 accretion is certainly the first one of 366 00:17:54,279 --> 00:17:52,279 which I'm aware and so on the one hand 367 00:17:55,750 --> 00:17:54,289 everyone has always predicted this but 368 00:17:57,730 --> 00:17:55,760 on the other hand to actually be able to 369 00:18:00,789 --> 00:17:57,740 see it and have it come out so simply 370 00:18:02,230 --> 00:18:00,799 and such hey an imitation of the cartoon 371 00:18:04,720 --> 00:18:02,240 that you would draw to me is really 372 00:18:07,029 --> 00:18:04,730 remarkable right well I think we've got 373 00:18:08,889 --> 00:18:07,039 to go back to Chris burrows and find out 374 00:18:09,420 --> 00:18:08,899 some more tell us tell us more about 375 00:18:11,580 --> 00:18:09,430 what 376 00:18:15,750 --> 00:18:11,590 design and the center of these stars 377 00:18:18,710 --> 00:18:15,760 information well the these images 378 00:18:22,560 --> 00:18:18,720 actually were were first captured in 379 00:18:24,270 --> 00:18:22,570 January of a fabulet last year and we 380 00:18:25,800 --> 00:18:24,280 were so excited to see this object but 381 00:18:27,240 --> 00:18:25,810 we had to come back to it with Hubble 382 00:18:31,050 --> 00:18:27,250 and get a second image so one thing I'm 383 00:18:32,340 --> 00:18:31,060 going to show you is is an image this is 384 00:18:34,710 --> 00:18:32,350 actually the second image we've taken 385 00:18:36,630 --> 00:18:34,720 and it's another version of the image 386 00:18:38,850 --> 00:18:36,640 you just saw just displayed in a 387 00:18:40,890 --> 00:18:38,860 different way and you can clearly see 388 00:18:43,500 --> 00:18:40,900 here these knots of material coming out 389 00:18:45,270 --> 00:18:43,510 from the star in the jet and again each 390 00:18:47,850 --> 00:18:45,280 pixel in this image each little square 391 00:18:50,340 --> 00:18:47,860 block that you see is about 14 392 00:18:53,190 --> 00:18:50,350 astronomical units across so that the 393 00:18:54,960 --> 00:18:53,200 our solar system's 80 astronomical units 394 00:18:57,690 --> 00:18:54,970 across so our solar system fits right in 395 00:19:00,090 --> 00:18:57,700 there so we're seeing the material that 396 00:19:01,740 --> 00:19:00,100 might eventually form a planetary system 397 00:19:03,620 --> 00:19:01,750 around this star and we're seeing the 398 00:19:06,630 --> 00:19:03,630 jet as it comes out from this disk 399 00:19:08,810 --> 00:19:06,640 directly for the first time and it's 400 00:19:11,280 --> 00:19:08,820 also clear I guess that the jet 401 00:19:13,740 --> 00:19:11,290 collimation that the thing that can find 402 00:19:14,850 --> 00:19:13,750 the jet in this pencil beam really 403 00:19:17,070 --> 00:19:14,860 doesn't have very much to do with the 404 00:19:18,270 --> 00:19:17,080 shape of the disk as had been theorized 405 00:19:19,770 --> 00:19:18,280 it this has to be something that's 406 00:19:22,800 --> 00:19:19,780 happening much closer to the star than 407 00:19:25,830 --> 00:19:22,810 than the disc itself this is much 408 00:19:27,450 --> 00:19:25,840 narrower than the Thunder and the cavity 409 00:19:30,240 --> 00:19:27,460 in the disk right and the little black 410 00:19:32,310 --> 00:19:30,250 spots along the red jet are the 411 00:19:34,080 --> 00:19:32,320 individual little lumps no that was 412 00:19:36,570 --> 00:19:34,090 actually the red jet itself maybe we can 413 00:19:40,560 --> 00:19:36,580 put the image up a moment the red the 414 00:19:42,420 --> 00:19:40,570 jet the red spots you see a knot in the 415 00:19:44,160 --> 00:19:42,430 jet that are propagating away from the 416 00:19:46,230 --> 00:19:44,170 star and then you can see a hint here of 417 00:19:47,430 --> 00:19:46,240 the of the jet on the other side so 418 00:19:49,470 --> 00:19:47,440 these blobs we actually know are moving 419 00:19:52,320 --> 00:19:49,480 the other direction perhaps to visualize 420 00:19:53,490 --> 00:19:52,330 this in three dimensions with John 421 00:19:56,310 --> 00:19:53,500 Christie at the Space Telescope 422 00:19:58,620 --> 00:19:56,320 Institute Kyle snapple felt at JPL and 423 00:20:00,440 --> 00:19:58,630 Alan Watson at lowell observatory I made 424 00:20:03,570 --> 00:20:00,450 a simulation which I'd like to show 425 00:20:04,800 --> 00:20:03,580 which illustrates in perhaps in three 426 00:20:07,530 --> 00:20:04,810 dimensions and this is a full physical 427 00:20:09,210 --> 00:20:07,540 model of what's going on what you see 428 00:20:11,040 --> 00:20:09,220 here is a rotator is the whole system 429 00:20:13,650 --> 00:20:11,050 rotating so you can see it from many 430 00:20:15,270 --> 00:20:13,660 different angles and this is we've been 431 00:20:17,130 --> 00:20:15,280 able to describe in three dimensions 432 00:20:18,960 --> 00:20:17,140 what the distribution of material in the 433 00:20:20,670 --> 00:20:18,970 disc looks like and you can see that the 434 00:20:23,190 --> 00:20:20,680 model fits very nicely onto the data 435 00:20:25,019 --> 00:20:23,200 that we've got so we're understanding 436 00:20:26,700 --> 00:20:25,029 in detail what's happening in this in 437 00:20:28,080 --> 00:20:26,710 the system we're understanding you know 438 00:20:29,879 --> 00:20:28,090 what the density is a function of 439 00:20:31,259 --> 00:20:29,889 position and then that will help us to 440 00:20:33,330 --> 00:20:31,269 build models which will explain how 441 00:20:37,470 --> 00:20:33,340 eventually you could build planets for 442 00:20:39,889 --> 00:20:37,480 example okay well we've seen Jeff Hess 443 00:20:43,289 --> 00:20:39,899 sir we've seen a at least four different 444 00:20:45,419 --> 00:20:43,299 her big arrow objects to the uninitiated 445 00:20:47,340 --> 00:20:45,429 like myself they all look their friend I 446 00:20:48,899 --> 00:20:47,350 suspect we'll see some more before we're 447 00:20:50,700 --> 00:20:48,909 done today there ain't commonality in 448 00:20:52,019 --> 00:20:50,710 all of this is well that's that's really 449 00:20:54,779 --> 00:20:52,029 one of the exciting things about these 450 00:20:56,610 --> 00:20:54,789 data often in astronomy we go and look 451 00:20:58,200 --> 00:20:56,620 at this object and say wow that's wild 452 00:21:00,720 --> 00:20:58,210 and then we look at this object and say 453 00:21:02,340 --> 00:21:00,730 wow that's wild but here we're looking 454 00:21:04,500 --> 00:21:02,350 at a number of different objects and 455 00:21:06,029 --> 00:21:04,510 we're getting the same common picture 456 00:21:07,680 --> 00:21:06,039 out of all of them and tells us that 457 00:21:09,870 --> 00:21:07,690 we're really seeing not special 458 00:21:12,990 --> 00:21:09,880 circumstances but really we're seeing a 459 00:21:14,820 --> 00:21:13,000 picture of how it is that stars form as 460 00:21:16,889 --> 00:21:14,830 a way of seeing that Chris was just 461 00:21:19,169 --> 00:21:16,899 showing you a model of what's going on 462 00:21:21,090 --> 00:21:19,179 in HH 30 with the disc and such as that 463 00:21:25,320 --> 00:21:21,100 and if we could have the next graphic 464 00:21:28,200 --> 00:21:25,330 here this is exactly the same model the 465 00:21:30,149 --> 00:21:28,210 Chris was showing you for HH 30 except 466 00:21:32,159 --> 00:21:30,159 this model has been turned on in the 467 00:21:35,669 --> 00:21:32,169 little bit and so if you look at this 468 00:21:38,519 --> 00:21:35,679 model what you see now is you see the 469 00:21:40,649 --> 00:21:38,529 jet coming out away from the start very 470 00:21:42,950 --> 00:21:40,659 narrow at the end you then see what 471 00:21:45,509 --> 00:21:42,960 appears to be kind of a conical 472 00:21:47,669 --> 00:21:45,519 reflection nebula here that's the top of 473 00:21:49,379 --> 00:21:47,679 the disk and then you don't see the jet 474 00:21:52,070 --> 00:21:49,389 on the other side because on the other 475 00:21:55,470 --> 00:21:52,080 side the jet is in fact hiding behind 476 00:21:57,960 --> 00:21:55,480 the material on the disk when we look at 477 00:22:00,990 --> 00:21:57,970 HH 34 which was the same object that we 478 00:22:03,539 --> 00:22:01,000 looked at before we see a picture that 479 00:22:07,080 --> 00:22:03,549 looks very much like this model we can 480 00:22:08,879 --> 00:22:07,090 have that graphic please in HH 34 keep 481 00:22:11,220 --> 00:22:08,889 the model that you just saw in mind and 482 00:22:13,649 --> 00:22:11,230 look at what we have here down at one 483 00:22:17,190 --> 00:22:13,659 end the star itself is at this location 484 00:22:19,590 --> 00:22:17,200 and we see kind of a conical reflection 485 00:22:21,600 --> 00:22:19,600 nebula which is exactly what we saw in 486 00:22:24,690 --> 00:22:21,610 that model of HH 30 when we turned it on 487 00:22:27,240 --> 00:22:24,700 end we then see the jet coming out again 488 00:22:29,430 --> 00:22:27,250 very very thin right down at the tip and 489 00:22:31,769 --> 00:22:29,440 expanding somewhat as it moves out 490 00:22:34,529 --> 00:22:31,779 through interstellar space again just as 491 00:22:36,419 --> 00:22:34,539 we saw in the model of HH 30 and finally 492 00:22:36,840 --> 00:22:36,429 we see the difference between this model 493 00:22:39,420 --> 00:22:36,850 in nature 494 00:22:41,970 --> 00:22:39,430 30 is that there is no jet here on the 495 00:22:44,010 --> 00:22:41,980 other side it's actually there it's just 496 00:22:46,560 --> 00:22:44,020 that we can't see it because it's hiding 497 00:22:49,500 --> 00:22:46,570 behind that very dense disk from which 498 00:22:50,970 --> 00:22:49,510 the star itself is forming while this 499 00:22:52,710 --> 00:22:50,980 picture is up the other thing that I'll 500 00:22:54,480 --> 00:22:52,720 talk about that's common between these 501 00:22:56,790 --> 00:22:54,490 observations is the picture that we're 502 00:22:58,920 --> 00:22:56,800 getting of these knots again I mentioned 503 00:23:00,750 --> 00:22:58,930 in my opening comments that many 504 00:23:03,960 --> 00:23:00,760 astronomers thought for a long time that 505 00:23:06,270 --> 00:23:03,970 just a smooth flow of material was 506 00:23:08,400 --> 00:23:06,280 coming out from the star and that the 507 00:23:09,990 --> 00:23:08,410 knots that they saw from the ground were 508 00:23:12,720 --> 00:23:10,000 things that were kind of happening 509 00:23:15,450 --> 00:23:12,730 inside that smooth flow of material here 510 00:23:18,270 --> 00:23:15,460 though we clearly see for example here a 511 00:23:20,700 --> 00:23:18,280 clump with its own little bow wave or 512 00:23:23,700 --> 00:23:20,710 hear a clump with its own little bow 513 00:23:25,410 --> 00:23:23,710 wave and if you look at all of the jets 514 00:23:28,650 --> 00:23:25,420 that we see today you get that same 515 00:23:30,900 --> 00:23:28,660 basic picture that these are bursts that 516 00:23:33,720 --> 00:23:30,910 are happening that the star does 517 00:23:35,970 --> 00:23:33,730 something and it spits out material and 518 00:23:37,890 --> 00:23:35,980 so these bursts are not talking is 519 00:23:40,140 --> 00:23:37,900 telling us something about you know some 520 00:23:42,450 --> 00:23:40,150 esoteric piece of gas dynamics that 521 00:23:44,910 --> 00:23:42,460 happens as Jets travel through 522 00:23:47,670 --> 00:23:44,920 interstellar space instead it's telling 523 00:23:49,320 --> 00:23:47,680 us that stars when they form for reasons 524 00:23:52,410 --> 00:23:49,330 that are not entirely clear to us yet 525 00:23:54,300 --> 00:23:52,420 stars when they form from the very inner 526 00:23:58,110 --> 00:23:54,310 most part of that disc in the star 527 00:24:00,450 --> 00:23:58,120 itself are episodic they do something 528 00:24:02,190 --> 00:24:00,460 for a while and then they go burst and 529 00:24:04,200 --> 00:24:02,200 they send out a burst of material and 530 00:24:05,910 --> 00:24:04,210 understanding the physics of why that 531 00:24:07,920 --> 00:24:05,920 happens is going to be something that 532 00:24:09,600 --> 00:24:07,930 any successful model of star formation 533 00:24:13,920 --> 00:24:09,610 is going to have to come to grips with 534 00:24:15,900 --> 00:24:13,930 okay now thanks Jeff talking about these 535 00:24:18,450 --> 00:24:15,910 moving knots I think Chris burrows you 536 00:24:20,430 --> 00:24:18,460 have couple images that blink them for 537 00:24:22,260 --> 00:24:20,440 us right well I was how you measured 538 00:24:24,240 --> 00:24:22,270 their motion yeah I actually mentioned 539 00:24:26,340 --> 00:24:24,250 we saw this intriguing object laughs 540 00:24:28,440 --> 00:24:26,350 februari and we were determined to come 541 00:24:30,090 --> 00:24:28,450 back and take a second look so the first 542 00:24:33,030 --> 00:24:30,100 look that we got actually is on the 543 00:24:35,310 --> 00:24:33,040 screen now and we could take a look at 544 00:24:37,230 --> 00:24:35,320 it what you see here these arrows are 545 00:24:39,690 --> 00:24:37,240 pointing to some knots in the jet that 546 00:24:43,440 --> 00:24:39,700 we saw this was in January of 90 in 547 00:24:45,390 --> 00:24:43,450 February of 94 and then we took another 548 00:24:47,610 --> 00:24:45,400 image in January this year and this is 549 00:24:49,480 --> 00:24:47,620 the image that we saw then and you can 550 00:24:51,070 --> 00:24:49,490 see that the knots have moved 551 00:24:53,410 --> 00:24:51,080 in fact if you blink backwards and 552 00:24:55,419 --> 00:24:53,420 forwards between these two images you 553 00:24:58,330 --> 00:24:55,429 can see the knots are moving and because 554 00:25:00,460 --> 00:24:58,340 we know how long ago that far apart in 555 00:25:02,470 --> 00:25:00,470 time the images were taken and how far 556 00:25:05,320 --> 00:25:02,480 away this object is we can compute how 557 00:25:07,419 --> 00:25:05,330 fast the jet is moving it turns out for 558 00:25:10,090 --> 00:25:07,429 example that the top job not there which 559 00:25:13,090 --> 00:25:10,100 is the one moving fastest is moving at 560 00:25:15,280 --> 00:25:13,100 something like 300 miles a second which 561 00:25:17,169 --> 00:25:15,290 is if you like a thousandth of the speed 562 00:25:18,520 --> 00:25:17,179 of light so these are very energetic 563 00:25:20,049 --> 00:25:18,530 outflows that we're seeing which is why 564 00:25:24,520 --> 00:25:20,059 they're able to propagate for hundreds 565 00:25:27,430 --> 00:25:24,530 of billions of miles so now it's not a 566 00:25:30,190 --> 00:25:27,440 matter of some kind of indirect esoteric 567 00:25:31,690 --> 00:25:30,200 a guess and how quickly these blobs are 568 00:25:33,310 --> 00:25:31,700 coasting out you're actually just 569 00:25:34,930 --> 00:25:33,320 watching the motion from month to month 570 00:25:36,580 --> 00:25:34,940 a month and measuring it directly is 571 00:25:38,380 --> 00:25:36,590 that right that that's right although 572 00:25:39,910 --> 00:25:38,390 we've been able to do this on the ground 573 00:25:41,620 --> 00:25:39,920 but it's always taken years and years 574 00:25:43,180 --> 00:25:41,630 before you'd have to look so that you 575 00:25:45,190 --> 00:25:43,190 could detect this motion from the ground 576 00:25:46,750 --> 00:25:45,200 and that may take five or ten years now 577 00:25:48,940 --> 00:25:46,760 we're able to just measure it directly 578 00:25:50,620 --> 00:25:48,950 in the space of 12 months and that means 579 00:25:52,690 --> 00:25:50,630 that we can follow individual block 580 00:25:54,669 --> 00:25:52,700 blobs through the you know through the 581 00:25:57,190 --> 00:25:54,679 the kinks in the Jets and see how they 582 00:25:58,870 --> 00:25:57,200 behave during those during those changes 583 00:26:00,850 --> 00:25:58,880 in direction one of the one of the 584 00:26:03,190 --> 00:26:00,860 mysteries which was Jeff may come back 585 00:26:05,140 --> 00:26:03,200 to is why there are these kinks in the 586 00:26:06,940 --> 00:26:05,150 Jets what's causing them now we'll be 587 00:26:08,680 --> 00:26:06,950 able to literally take a video of the of 588 00:26:10,630 --> 00:26:08,690 these knots as they go through the kinks 589 00:26:11,770 --> 00:26:10,640 and understand better whether the knots 590 00:26:14,110 --> 00:26:11,780 always keep going in the same direction 591 00:26:15,820 --> 00:26:14,120 or whether they deviate and follow along 592 00:26:17,200 --> 00:26:15,830 the jet as it bends through space and 593 00:26:18,790 --> 00:26:17,210 what would this why hasn't this been 594 00:26:20,110 --> 00:26:18,800 done before what would this image look 595 00:26:21,820 --> 00:26:20,120 like if you took it from a ground-based 596 00:26:25,360 --> 00:26:21,830 telescope well from the ground you 597 00:26:26,830 --> 00:26:25,370 simply the central the central disc that 598 00:26:30,310 --> 00:26:26,840 you're seeing this yellow and the in the 599 00:26:32,290 --> 00:26:30,320 image would be would be unresolved you'd 600 00:26:34,060 --> 00:26:32,300 see a fuzzy blob but you wouldn't be 601 00:26:36,940 --> 00:26:34,070 able to tell that it wasn't just a point 602 00:26:39,850 --> 00:26:36,950 star and in the knots here remember this 603 00:26:41,320 --> 00:26:39,860 is the closest example the knots here 604 00:26:42,970 --> 00:26:41,330 from the ground will be very difficult 605 00:26:44,650 --> 00:26:42,980 to resolve there are only a few tenths 606 00:26:45,940 --> 00:26:44,660 of an arcsecond department so the whole 607 00:26:47,650 --> 00:26:45,950 thing what Billy just look like one 608 00:26:48,850 --> 00:26:47,660 fuzzy mushroom right you'd see that 609 00:26:50,320 --> 00:26:48,860 there was a jet there but you wouldn't 610 00:26:51,640 --> 00:26:50,330 be able to resolve easily the individual 611 00:26:53,520 --> 00:26:51,650 components and unfortunate that the 612 00:26:55,990 --> 00:26:53,530 nearest one has just the ideal 613 00:26:58,120 --> 00:26:56,000 orientation to our view that it's in 614 00:26:59,830 --> 00:26:58,130 profile we learnt there are a number of 615 00:27:01,750 --> 00:26:59,840 stars in this star forming region we've 616 00:27:03,020 --> 00:27:01,760 looked at this is easily the best 617 00:27:04,910 --> 00:27:03,030 example I see 618 00:27:07,790 --> 00:27:04,920 okay I think we want to look into the 619 00:27:10,070 --> 00:27:07,800 physics a little and ask Jeff fester and 620 00:27:11,630 --> 00:27:10,080 John Morse you know what do you think 621 00:27:14,330 --> 00:27:11,640 makes these things come out at 622 00:27:15,920 --> 00:27:14,340 methodically and and if you want to get 623 00:27:17,720 --> 00:27:15,930 into the kinks tell us about that too 624 00:27:19,970 --> 00:27:17,730 well the the physics is the right word 625 00:27:22,130 --> 00:27:19,980 the you know one of the very most 626 00:27:24,740 --> 00:27:22,140 exciting things about this is that we're 627 00:27:27,020 --> 00:27:24,750 finally getting a close enough look at 628 00:27:29,300 --> 00:27:27,030 what's going on that we can start doing 629 00:27:32,030 --> 00:27:29,310 some physics for some years people have 630 00:27:33,950 --> 00:27:32,040 been calculating models using computers 631 00:27:37,310 --> 00:27:33,960 to do simulations of what should be 632 00:27:38,990 --> 00:27:37,320 happening in these Jets and they've been 633 00:27:40,370 --> 00:27:39,000 calculating these models and we all go 634 00:27:42,230 --> 00:27:40,380 off to meetings and look at them and say 635 00:27:43,820 --> 00:27:42,240 oh that's very pretty but then we've 636 00:27:46,010 --> 00:27:43,830 been turning through our data and our 637 00:27:48,770 --> 00:27:46,020 data been of such a quality that we just 638 00:27:50,420 --> 00:27:48,780 couldn't do a real comparison between 639 00:27:52,520 --> 00:27:50,430 what we were seeing in the models in 640 00:27:54,140 --> 00:27:52,530 between what we were seeing in the real 641 00:27:55,910 --> 00:27:54,150 universe have more detailed in the 642 00:27:57,920 --> 00:27:55,920 picture Jerry had more details in the 643 00:27:59,960 --> 00:27:57,930 pictures the exciting thing here is that 644 00:28:02,360 --> 00:27:59,970 we're finally actually able to see the 645 00:28:05,450 --> 00:28:02,370 real objects well enough to start doing 646 00:28:07,010 --> 00:28:05,460 that comparison we have a simulation 647 00:28:09,920 --> 00:28:07,020 here in fact this is a simulation that 648 00:28:12,290 --> 00:28:09,930 was carried out by a gemstone is at the 649 00:28:16,250 --> 00:28:12,300 University of Maryland and what he did 650 00:28:18,470 --> 00:28:16,260 is calculate what happens when a jet a 651 00:28:20,930 --> 00:28:18,480 pulse jet consisting of lots of little 652 00:28:23,450 --> 00:28:20,940 bursts comes flying out into the 653 00:28:25,580 --> 00:28:23,460 surrounding interstellar gas and what 654 00:28:26,870 --> 00:28:25,590 you see here these individual if I could 655 00:28:28,970 --> 00:28:26,880 have a cursor on please a little 656 00:28:31,460 --> 00:28:28,980 motorboat the little motor boats exactly 657 00:28:33,890 --> 00:28:31,470 these individual knots are the pulses 658 00:28:36,500 --> 00:28:33,900 that are coming out from the source and 659 00:28:39,200 --> 00:28:36,510 you see that as they move along each one 660 00:28:41,510 --> 00:28:39,210 has its own little bow wave just like a 661 00:28:43,040 --> 00:28:41,520 motor boat has its little bow wave which 662 00:28:44,840 --> 00:28:43,050 is exactly the kind of structure that 663 00:28:47,210 --> 00:28:44,850 we're seeing when we're looking at these 664 00:28:48,830 --> 00:28:47,220 jets and so all you have to do it was 665 00:28:50,750 --> 00:28:48,840 when we got these data it was really 666 00:28:53,110 --> 00:28:50,760 exciting because we had seen these 667 00:28:55,400 --> 00:28:53,120 models for the past several years and 668 00:28:57,350 --> 00:28:55,410 when you first looked at the hubble 669 00:28:59,390 --> 00:28:57,360 space telescope images of these jets it 670 00:29:01,490 --> 00:28:59,400 was like saying WOW I've seen that 671 00:29:03,170 --> 00:29:01,500 picture before except it wasn't a 672 00:29:04,820 --> 00:29:03,180 picture of something in space really 673 00:29:06,650 --> 00:29:04,830 instead it was a picture of somebody's 674 00:29:08,360 --> 00:29:06,660 calculation of what should be in space 675 00:29:10,040 --> 00:29:08,370 and that's the kind of thing that when 676 00:29:12,440 --> 00:29:10,050 it happens for an astronomer it's really 677 00:29:13,910 --> 00:29:12,450 very very exciting because it tells you 678 00:29:16,040 --> 00:29:13,920 just almost instantly that there's 679 00:29:18,500 --> 00:29:16,050 something that now you understand that 680 00:29:20,330 --> 00:29:18,510 or you didn't another piece of that 681 00:29:23,110 --> 00:29:20,340 model that you just saw was the 682 00:29:26,360 --> 00:29:23,120 individual blobs of gas coming along and 683 00:29:28,070 --> 00:29:26,370 running into the bow wave at the end so 684 00:29:29,900 --> 00:29:28,080 this material was coming along and one 685 00:29:32,270 --> 00:29:29,910 not hit smack and then the next not 686 00:29:34,370 --> 00:29:32,280 caught up with it and smack over and 687 00:29:37,430 --> 00:29:34,380 over again well when you look at another 688 00:29:39,650 --> 00:29:37,440 object this is a HH one if I could have 689 00:29:42,710 --> 00:29:39,660 the next graphic please another very 690 00:29:45,020 --> 00:29:42,720 exciting thing was that we saw exactly 691 00:29:46,610 --> 00:29:45,030 the same phenomena there this is another 692 00:29:48,350 --> 00:29:46,620 Hubble Space toss this is another Hubble 693 00:29:49,700 --> 00:29:48,360 Space Telescope image this is in fact a 694 00:29:52,430 --> 00:29:49,710 blow-up of the first Hubble Space 695 00:29:53,960 --> 00:29:52,440 Telescope image that I showed you and if 696 00:29:55,880 --> 00:29:53,970 I could have the graphic in the and the 697 00:29:59,030 --> 00:29:55,890 cursor again please what you're seeing 698 00:30:02,000 --> 00:29:59,040 here is the jet is coming in from this 699 00:30:04,520 --> 00:30:02,010 direction and it's smacking into the 700 00:30:06,890 --> 00:30:04,530 interstellar gas right here and so these 701 00:30:10,130 --> 00:30:06,900 individual pulses are coming in over and 702 00:30:12,230 --> 00:30:10,140 over again wham wham wham and what we 703 00:30:15,560 --> 00:30:12,240 saw here that was really fascinating is 704 00:30:18,140 --> 00:30:15,570 that right up here at the very front of 705 00:30:21,380 --> 00:30:18,150 this is the bow wave of one of those 706 00:30:24,710 --> 00:30:21,390 pulses and then immediately behind it 707 00:30:26,750 --> 00:30:24,720 coming right up on its wake is the bow 708 00:30:28,940 --> 00:30:26,760 wave of another one of those pulses and 709 00:30:31,240 --> 00:30:28,950 so not only are we getting to see the 710 00:30:33,740 --> 00:30:31,250 detailed physics of the jet itself and 711 00:30:35,540 --> 00:30:33,750 speculate about what that jet tells us 712 00:30:37,400 --> 00:30:35,550 about the star and the star formation 713 00:30:39,230 --> 00:30:37,410 we're also getting to look at the other 714 00:30:41,450 --> 00:30:39,240 end of it and seeing the effects of 715 00:30:43,550 --> 00:30:41,460 these individual pulses coming in and 716 00:30:45,260 --> 00:30:43,560 one after the other running into the 717 00:30:47,990 --> 00:30:45,270 clouds of interstellar gas that's around 718 00:30:50,180 --> 00:30:48,000 this object so it's really very exciting 719 00:30:54,980 --> 00:30:50,190 stuff John Morris what what causes those 720 00:30:58,010 --> 00:30:54,990 pulses well I wouldn't know but there 721 00:31:03,590 --> 00:30:58,020 are people who might have an idea out 722 00:31:05,780 --> 00:31:03,600 there determining that a the jet comes 723 00:31:07,820 --> 00:31:05,790 from a very narrow region close to the 724 00:31:10,520 --> 00:31:07,830 star is a huge result in these 725 00:31:14,230 --> 00:31:10,530 observations secondly determining that 726 00:31:17,510 --> 00:31:14,240 the jet is intrinsically pulsed is 727 00:31:19,790 --> 00:31:17,520 another huge result it means that wild 728 00:31:23,360 --> 00:31:19,800 matter is what falling down in the star 729 00:31:24,200 --> 00:31:23,370 there's some sort of episodic phenomenon 730 00:31:28,670 --> 00:31:24,210 occurring 731 00:31:32,870 --> 00:31:28,680 now what that phenomenon is is open to 732 00:31:35,720 --> 00:31:32,880 debate there are objects such as dwarf 733 00:31:38,030 --> 00:31:35,730 novae which people know our binary 734 00:31:43,490 --> 00:31:38,040 systems which involve accretion disks 735 00:31:45,940 --> 00:31:43,500 onto a white dwarf and these objects 736 00:31:49,430 --> 00:31:45,950 which have accretion disk around them 737 00:31:51,770 --> 00:31:49,440 actually go through unstable periods and 738 00:31:53,960 --> 00:31:51,780 they have outburst and so matter might 739 00:31:55,760 --> 00:31:53,970 build up and then it would release and 740 00:31:58,070 --> 00:31:55,770 then for a time the matter would build 741 00:32:03,230 --> 00:31:58,080 up again and release again so you might 742 00:32:06,860 --> 00:32:03,240 get episodic ejections or outbursts with 743 00:32:09,410 --> 00:32:06,870 a disk phenomenon now the other 744 00:32:11,810 --> 00:32:09,420 interesting analogy with that object is 745 00:32:14,270 --> 00:32:11,820 that those objects don't always have the 746 00:32:16,490 --> 00:32:14,280 same size outbursts sometimes the 747 00:32:18,080 --> 00:32:16,500 outbursts are big sometimes the 748 00:32:20,210 --> 00:32:18,090 outbursts are small and we do see 749 00:32:21,680 --> 00:32:20,220 evidence for that in these stellar Jets 750 00:32:24,470 --> 00:32:21,690 that there are different sizes of 751 00:32:28,810 --> 00:32:24,480 outbursts perhaps we might debate that a 752 00:32:34,220 --> 00:32:31,760 another phenomenon we see is that all of 753 00:32:36,800 --> 00:32:34,230 the Jets that we've imaged although 754 00:32:38,960 --> 00:32:36,810 they're straight and narrow which and 755 00:32:42,320 --> 00:32:38,970 how narrow they are is quite remarkable 756 00:32:44,540 --> 00:32:42,330 all of the Jets show signs or some sort 757 00:32:46,340 --> 00:32:44,550 of wiggling motion that they don't go 758 00:32:48,800 --> 00:32:46,350 perfectly straight they tend to bend 759 00:32:52,940 --> 00:32:48,810 around a little bit now if we can bring 760 00:32:56,720 --> 00:32:52,950 up the HH 47 HST image we could actually 761 00:33:01,640 --> 00:32:56,730 see global Telescope image that's right 762 00:33:04,070 --> 00:33:01,650 the wiggling in this particular jet is 763 00:33:05,900 --> 00:33:04,080 more exaggerated than the other ones we 764 00:33:07,970 --> 00:33:05,910 saw to remind you again the star is 765 00:33:12,320 --> 00:33:07,980 right here in the cloud and the jet is 766 00:33:16,190 --> 00:33:12,330 moving off to the upper left there's a 767 00:33:18,890 --> 00:33:16,200 wiggle here another one over here it's 768 00:33:20,870 --> 00:33:18,900 hard to say whether the jet actually 769 00:33:22,820 --> 00:33:20,880 bounces back and forth here or whether 770 00:33:25,730 --> 00:33:22,830 we're just seeing emission on the 771 00:33:28,540 --> 00:33:25,740 surface of the jet which is actually 772 00:33:31,280 --> 00:33:28,550 moving along here but there are clearly 773 00:33:34,010 --> 00:33:31,290 lots of Wiggles and curves in here when 774 00:33:35,630 --> 00:33:34,020 people look at this image the first 775 00:33:37,850 --> 00:33:35,640 thing they think of is like a corkscrew 776 00:33:40,400 --> 00:33:37,860 it looks like the jet may actually 777 00:33:42,669 --> 00:33:40,410 spirally the gas are there and we know 778 00:33:47,180 --> 00:33:42,679 that's definitely not what's occurring 779 00:33:51,980 --> 00:33:47,190 so this jet goes fast down the middle 780 00:33:57,130 --> 00:33:51,990 and slow at the edges and we have curb 781 00:34:01,850 --> 00:33:59,600 well John couldn't it be what's going on 782 00:34:04,460 --> 00:34:01,860 is that the nozzle that's ejecting the 783 00:34:08,149 --> 00:34:04,470 jet is itself undergoing these gyrations 784 00:34:10,129 --> 00:34:08,159 it's it's possible and immediately when 785 00:34:12,859 --> 00:34:10,139 you think of precession or some sort of 786 00:34:15,139 --> 00:34:12,869 motion of the source you have to bring 787 00:34:18,260 --> 00:34:15,149 in a component especially when the axis 788 00:34:21,800 --> 00:34:18,270 wobbles around you have to bring in 789 00:34:23,510 --> 00:34:21,810 another another star into the picture it 790 00:34:27,649 --> 00:34:23,520 is known that many of the sources of 791 00:34:30,109 --> 00:34:27,659 these Jets are in fact binaries but 792 00:34:32,090 --> 00:34:30,119 whether all of them are is open to 793 00:34:34,580 --> 00:34:32,100 question yet one of the one of the 794 00:34:36,290 --> 00:34:34,590 exciting things as we've been getting 795 00:34:37,490 --> 00:34:36,300 ready for this presentation in the last 796 00:34:39,590 --> 00:34:37,500 couple of days and we've been arguing 797 00:34:41,930 --> 00:34:39,600 among ourselves what it means they're 798 00:34:44,419 --> 00:34:41,940 all manner of models that you can come 799 00:34:45,859 --> 00:34:44,429 up with unless one or two okay you look 800 00:34:47,810 --> 00:34:45,869 for example if you look at the time 801 00:34:50,210 --> 00:34:47,820 scales for these pulses they range 802 00:34:52,520 --> 00:34:50,220 anywhere from a few years to a few tens 803 00:34:54,680 --> 00:34:52,530 of years and that's the same kind of 804 00:34:56,629 --> 00:34:54,690 time that it takes say for a large 805 00:34:58,640 --> 00:34:56,639 planet to orbit around the star or the 806 00:35:00,920 --> 00:34:58,650 kind of time that it takes for two stars 807 00:35:03,170 --> 00:35:00,930 to orbit around each other but it's also 808 00:35:05,750 --> 00:35:03,180 the kind of time that it takes say for 809 00:35:07,640 --> 00:35:05,760 the sun's magnetic field to change 810 00:35:09,620 --> 00:35:07,650 directions and we know that there's a 811 00:35:12,230 --> 00:35:09,630 good chance that these disks or that 812 00:35:14,630 --> 00:35:12,240 these disks and jets are strongly 813 00:35:18,080 --> 00:35:14,640 magnetic and that that's a major part of 814 00:35:19,730 --> 00:35:18,090 it lots of other speculation and again 815 00:35:21,859 --> 00:35:19,740 we're not giving you answers today but 816 00:35:23,780 --> 00:35:21,869 instead we're saying that there's lots 817 00:35:25,490 --> 00:35:23,790 of neat stuff in here and before we 818 00:35:28,250 --> 00:35:25,500 really say that we understand star 819 00:35:30,050 --> 00:35:28,260 formation we're going to have to say 820 00:35:31,609 --> 00:35:30,060 that we understand all these phenomena 821 00:35:34,310 --> 00:35:31,619 that we're speculating about today I'd 822 00:35:36,950 --> 00:35:34,320 like to interject first that actually we 823 00:35:40,160 --> 00:35:36,960 do not have direct evidence that the 824 00:35:42,200 --> 00:35:40,170 Jets are strongly magnetic we have in 825 00:35:45,740 --> 00:35:42,210 fact no evidence that the Jets are 826 00:35:48,170 --> 00:35:45,750 strongly magnetic we know we believe 827 00:35:51,109 --> 00:35:48,180 some work I did on my thesis I made 828 00:35:53,660 --> 00:35:51,119 estimates that there are at least some 829 00:35:55,849 --> 00:35:53,670 moderate magnetic fields far out in the 830 00:35:57,290 --> 00:35:55,859 Jets way far away from the star now 831 00:35:59,930 --> 00:35:57,300 those magnetic fields might be much 832 00:36:02,599 --> 00:35:59,940 larger near the star were the whole 833 00:36:04,880 --> 00:36:02,609 structures are compressed okay but i 834 00:36:07,400 --> 00:36:04,890 would say that proudly magnetic fields 835 00:36:10,880 --> 00:36:07,410 as far as the dynamics of the Jets don't 836 00:36:12,770 --> 00:36:10,890 have much to do with the real shape of 837 00:36:14,780 --> 00:36:12,780 well but there's a there's a response to 838 00:36:16,609 --> 00:36:14,790 that I'll get off pretty quickly there's 839 00:36:18,200 --> 00:36:16,619 a response to that and that is that we 840 00:36:19,910 --> 00:36:18,210 can see where the gas is there are two 841 00:36:22,010 --> 00:36:19,920 basic models for how these Jets are 842 00:36:24,109 --> 00:36:22,020 collimated one of those models is that 843 00:36:26,480 --> 00:36:24,119 there are magnetic fields that force the 844 00:36:28,190 --> 00:36:26,490 gas to flow along in that direction the 845 00:36:30,770 --> 00:36:28,200 other model is to say that there's gas 846 00:36:32,270 --> 00:36:30,780 around that contains the Jets and when 847 00:36:34,940 --> 00:36:32,280 you look at these pictures for example 848 00:36:37,160 --> 00:36:34,950 both the HH 34 and chris is HH 30 849 00:36:39,109 --> 00:36:37,170 observations you see that there isn't 850 00:36:40,609 --> 00:36:39,119 gas right around the Jets like that in 851 00:36:42,770 --> 00:36:40,619 fact that you see things are pretty well 852 00:36:44,330 --> 00:36:42,780 wide open and this jet comes screaming 853 00:36:45,920 --> 00:36:44,340 right out of the middle of it and it's 854 00:36:48,230 --> 00:36:45,930 hard for me to imagine how you're going 855 00:36:50,180 --> 00:36:48,240 to do that without invoking some strong 856 00:36:52,310 --> 00:36:50,190 role for magnetic field well I would say 857 00:36:55,870 --> 00:36:52,320 the role of the magnetic fields might be 858 00:36:58,820 --> 00:36:55,880 very important by those are all right 859 00:37:00,859 --> 00:36:58,830 return to in another five years or so 860 00:37:02,210 --> 00:37:00,869 there's going to be a new camera on the 861 00:37:04,070 --> 00:37:02,220 Hubble telescope will get even better 862 00:37:06,230 --> 00:37:04,080 pictures and maybe we'll hear more about 863 00:37:09,290 --> 00:37:06,240 it before then but right now I want to 864 00:37:12,680 --> 00:37:09,300 thank all the panelists and give this 865 00:37:15,170 --> 00:37:12,690 back to our announcer Don Savage Thank 866 00:37:20,050 --> 00:37:15,180 You Steven panelists will start taking 867 00:37:26,440 --> 00:37:22,970 up scheming please Kate wait for the 868 00:37:29,300 --> 00:37:26,450 microphone so we can get you picked up 869 00:37:34,550 --> 00:37:29,310 and a please state your name and 870 00:37:35,900 --> 00:37:34,560 affiliation thank you what are to the 871 00:37:38,599 --> 00:37:35,910 extent that it can be understood the 872 00:37:40,460 --> 00:37:38,609 range of masses either of the jets or of 873 00:37:41,990 --> 00:37:40,470 the proto stars that are forming if this 874 00:37:43,760 --> 00:37:42,000 is truly a common phenomenon the 875 00:37:46,670 --> 00:37:43,770 presumably of a range of masses that 876 00:37:48,680 --> 00:37:46,680 you're dealing with here yes the the 877 00:37:52,250 --> 00:37:48,690 protostars that we're all looking at 878 00:37:54,700 --> 00:37:52,260 probably have masses similar to those of 879 00:37:58,070 --> 00:37:54,710 our Sun or in fact may be much smaller 880 00:37:59,500 --> 00:37:58,080 these are all low mass stars as the 881 00:38:06,400 --> 00:37:59,510 range of stellar masses 882 00:38:09,670 --> 00:38:06,410 the masses in the Jets are yes much less 883 00:38:13,180 --> 00:38:09,680 but they're about 110 million of a solar 884 00:38:17,110 --> 00:38:13,190 mass lost per year in one of these Jets 885 00:38:18,820 --> 00:38:17,120 so in order to get an appreciable amount 886 00:38:21,280 --> 00:38:18,830 of mass loss in one of these Jets the 887 00:38:23,020 --> 00:38:21,290 Jets would have to be very old and like 888 00:38:25,510 --> 00:38:23,030 millions of years but they really aren't 889 00:38:29,160 --> 00:38:25,520 there maybe a hundred thousand years old 890 00:38:32,260 --> 00:38:29,170 at the most so the masses are very tiny 891 00:38:35,800 --> 00:38:32,270 now what fraction of the mass that's 892 00:38:37,870 --> 00:38:35,810 ejected in the jet as a fraction of how 893 00:38:39,460 --> 00:38:37,880 much is falling onto the star that still 894 00:38:41,800 --> 00:38:39,470 not real clear we know it's at least 895 00:38:44,080 --> 00:38:41,810 probably about ten percent but but maybe 896 00:38:46,180 --> 00:38:44,090 higher could be more and could explain 897 00:38:47,710 --> 00:38:46,190 why why you don't make much way you 898 00:38:50,200 --> 00:38:47,720 don't make massive stories you only make 899 00:38:52,180 --> 00:38:50,210 low mass stars this way in fact I think 900 00:38:56,140 --> 00:38:52,190 one of the most interesting things about 901 00:38:58,270 --> 00:38:56,150 these pictures is for years guided only 902 00:38:59,890 --> 00:38:58,280 by the extra galactic cases the flashy 903 00:39:02,170 --> 00:38:59,900 exploding galaxies that have jets 904 00:39:04,030 --> 00:39:02,180 astronomers are how are these jets made 905 00:39:05,890 --> 00:39:04,040 the details look so complicated and all 906 00:39:08,260 --> 00:39:05,900 that now I think we're beginning to 907 00:39:10,000 --> 00:39:08,270 realize that the answer is why doesn't 908 00:39:12,460 --> 00:39:10,010 everything have a jet that is it seems 909 00:39:15,130 --> 00:39:12,470 like that this the process of accretion 910 00:39:17,110 --> 00:39:15,140 is almost inevitably accompanied by the 911 00:39:19,390 --> 00:39:17,120 process of this narrow collimated 912 00:39:20,500 --> 00:39:19,400 expulsion the question is not how do you 913 00:39:21,970 --> 00:39:20,510 make Jetts it seems to be any the 914 00:39:24,100 --> 00:39:21,980 question is how do you avoid making Jets 915 00:39:26,400 --> 00:39:24,110 because here we look at the very closest 916 00:39:28,750 --> 00:39:26,410 cases of accretion that we can see 917 00:39:29,950 --> 00:39:28,760 anywhere in the universe named we think 918 00:39:32,320 --> 00:39:29,960 that are happening quite close to the 919 00:39:34,060 --> 00:39:32,330 Sun and we see these things that we used 920 00:39:36,910 --> 00:39:34,070 to think we're very exotic these over 921 00:39:39,310 --> 00:39:36,920 here at the birth of the Sun Bruce you 922 00:39:41,980 --> 00:39:39,320 would have seen an amazing fire rocket 923 00:39:43,990 --> 00:39:41,990 going up I i think the conclusion is 924 00:39:46,210 --> 00:39:44,000 becoming inescapable that you don't get 925 00:39:49,090 --> 00:39:46,220 accretion disks without also getting 926 00:39:50,950 --> 00:39:49,100 these narrow ejected fire hoses on all 927 00:39:54,010 --> 00:39:50,960 different spatial scales whether they 928 00:39:55,630 --> 00:39:54,020 are calm quiet formations of low-mass 929 00:39:58,600 --> 00:39:55,640 stars or whether there are these very 930 00:40:01,720 --> 00:39:58,610 violent accretion onto mass of nuclei of 931 00:40:03,520 --> 00:40:01,730 entire galaxies though even these events 932 00:40:06,670 --> 00:40:03,530 are not that common quiet given that the 933 00:40:09,040 --> 00:40:06,680 materials blasted off this as ionized 934 00:40:11,500 --> 00:40:09,050 plasma at hundreds of kilometers a 935 00:40:13,180 --> 00:40:11,510 second so we're talking a very energetic 936 00:40:14,829 --> 00:40:13,190 thing which is far more energy 937 00:40:15,760 --> 00:40:14,839 thick than the star is when it's finally 938 00:40:19,960 --> 00:40:15,770 been formed I wouldn't want to be 939 00:40:24,309 --> 00:40:19,970 standing in the way any further 940 00:40:25,720 --> 00:40:24,319 questions here at Goddard okay thank you 941 00:40:28,300 --> 00:40:25,730 understand that there are no questions 942 00:40:30,370 --> 00:40:28,310 from the other centers thank you for 943 00:40:33,040 --> 00:40:30,380 joining us today and thank you panelist