1 00:00:01,605 --> 00:00:05,924 A spectacular new image of an unusual spiral galaxy in the Coma Galaxy Cluster 2 00:00:05,959 --> 00:00:09,544 has been created from data taken by the Advanced Camera for Surveys 3 00:00:09,545 --> 00:00:12,827 on the NASA / ESA Hubble Space Telescope. 4 00:00:12,828 --> 00:00:17,801 It reveals lots of new details on the galaxy, NGC 4921, 5 00:00:17,802 --> 00:00:21,265 as well as an extraordinary rich background of more remote galaxies 6 00:00:21,300 --> 00:00:23,850 stretching back to the early Universe. 7 00:00:40,585 --> 00:00:42,517 This is the Hubblecast. 8 00:00:42,518 --> 00:00:46,188 News and images from the NASA / ESA Hubble Space Telescope. 9 00:00:46,189 --> 00:00:49,998 Travelling through time and space with our host, Dr. J 10 00:00:49,999 --> 00:00:52,321 EPISODE 26: Exceptionally deep view of strange galaxy. a.k.a. Dr. Joe Liske. 11 00:00:52,322 --> 00:00:55,290 Hello and welcome to another episode of the Hubblecast. 12 00:00:55,291 --> 00:00:57,427 I'm Richard Hook from ESO. 13 00:00:57,428 --> 00:01:00,342 Our usual host, Dr. J, has just had a baby daughter 14 00:01:00,385 --> 00:01:02,693 and will be on paternity leave for a while. 15 00:01:02,694 --> 00:01:06,083 So I'm here with short notice to tell you about the latest image from Hubble, 16 00:01:06,137 --> 00:01:08,915 a rather strange and ghostly galaxy. 17 00:01:10,814 --> 00:01:12,317 The Coma Galaxy Cluster, 18 00:01:12,354 --> 00:01:16,917 in the northern constellation of Coma Berenices, the hair of Queen Berenice, 19 00:01:16,918 --> 00:01:20,897 is one of the closest very rich collections of galaxies in the nearby Universe, 20 00:01:20,898 --> 00:01:23,700 and contains more than a thousand members. 21 00:01:23,701 --> 00:01:28,339 The brightest galaxies, including the one called NGC 4921, 22 00:01:28,340 --> 00:01:30,510 which we're going to talk about today, 23 00:01:30,511 --> 00:01:35,703 were discovered back in the late 18th century by the great astronomer William Herschel. 24 00:01:35,704 --> 00:01:39,060 Rich clusters like Coma are pretty crowded places, 25 00:01:39,061 --> 00:01:42,192 and galaxies undergo many interactions and mergers. 26 00:01:42,193 --> 00:01:45,833 This constant slow activity gradually turns spiral galaxies, 27 00:01:45,834 --> 00:01:47,779 which are rich in dust and gas, 28 00:01:47,780 --> 00:01:51,539 into clean elliptical systems without much active star formation. 29 00:01:51,540 --> 00:01:56,159 As a result, there are far more ellipticals and few spirals in the Coma Cluster, 30 00:01:56,160 --> 00:01:59,096 than are found in quieter corners of the Universe. 31 00:02:01,338 --> 00:02:04,470 The new Hubble picture shows NGC 4921, 32 00:02:04,530 --> 00:02:06,958 which is one of the rare spirals in Coma, 33 00:02:07,030 --> 00:02:08,492 and a rather unusual one. 34 00:02:09,280 --> 00:02:11,812 It's an example of an "anaemic spiral", 35 00:02:11,813 --> 00:02:14,445 were the normal lively star formation that creates 36 00:02:14,495 --> 00:02:18,790 a spiral galaxy's familiar brighter arms is much less intense. 37 00:02:19,195 --> 00:02:23,623 Because of this we can just see a delicate swirl of dust in a ring around the galaxy 38 00:02:23,624 --> 00:02:26,947 accompanied by some bright young blue stars in clusters 39 00:02:26,948 --> 00:02:29,994 that are clearly separated out by Hubble's sharp vision. 40 00:02:29,995 --> 00:02:34,188 Much of the pale spiral structure in the outer parts of the galaxy 41 00:02:34,189 --> 00:02:40,275 is unusually smooth and gives the whole galaxy the ghostly look of a vast, translucent jellyfish. 42 00:02:41,319 --> 00:02:43,806 This very long exposure Hubble picture 43 00:02:43,807 --> 00:02:47,582 shows us lots of fine detail in the galaxy and the Universe beyond. 44 00:02:48,115 --> 00:02:49,838 If we look more closely at the middle 45 00:02:49,899 --> 00:02:52,304 we can see that this galaxy has a bright nucleus 46 00:02:52,305 --> 00:02:55,665 with a straight bar extending to each side. 47 00:02:56,631 --> 00:03:01,671 Further out we can see a ring of dust and lots of hot young blue stars in clusters. 48 00:03:02,481 --> 00:03:04,317 Galaxies are quite transparent 49 00:03:04,318 --> 00:03:08,190 and we can see right through to much more remote galaxies far beyond. 50 00:03:10,669 --> 00:03:14,338 Further out we can see lots of dots that look a little like stars. 51 00:03:14,339 --> 00:03:17,444 These are actually very faint globular star clusters, 52 00:03:17,445 --> 00:03:21,406 huge balls of stars slowly orbiting the galaxies in the cluster. 53 00:03:25,789 --> 00:03:30,688 The image is filled with thousands of faint remote distant galaxies of all shapes and sizes. 54 00:03:30,944 --> 00:03:33,206 Some are normal but many of the fainter ones 55 00:03:33,207 --> 00:03:37,687 are blobby and chaotic star forming clumps, back in the early Universe. 56 00:03:37,688 --> 00:03:41,657 Far, far beyond the huge galaxy in the foreground. 57 00:03:42,931 --> 00:03:46,964 Also seen are foreground stars in our own Milky Way. 58 00:03:46,965 --> 00:03:52,714 Many galaxies have companions and NGC 4921 seems to be no exception. 59 00:03:52,715 --> 00:03:54,885 We could see several faint patches 60 00:03:54,886 --> 00:03:59,567 that are most likely to be smaller satellite systems orbiting their huge parent. 61 00:03:59,993 --> 00:04:04,906 Thanks for joining me for a quick tour of this stunning view of NGC 4921, 62 00:04:04,907 --> 00:04:07,931 a vast translucent jellyfish of a galaxy. 63 00:04:08,382 --> 00:04:11,124 This is Richard Hook signing off for the Hubblecast. 64 00:04:11,125 --> 00:04:15,669 Once again, nature has surprised us beyond our wildest imagination... 65 00:04:16,093 --> 00:04:18,093 Hubblecast is produced by ESA / Hubble 66 00:04:18,094 --> 00:04:20,094 at the European Southern Observatory in Germany. 67 00:04:20,876 --> 00:04:22,876 The Hubble mission is a project of international cooperation 68 00:04:22,877 --> 00:04:24,877 between NASA and the European Space Agency.