1 00:00:00,000 --> 00:00:04,000 The fiery subject of this new Hubble image 2 00:00:04,000 --> 00:00:08,000 may seem like it would be more at home in a Tolkien novel, 3 00:00:08,000 --> 00:00:14,000 but, it is actually a nebula known as the Ring Nebula, or Messier 57. 4 00:00:15,000 --> 00:00:19,000 Although this nebula is one of the most famous objects in our skies, 5 00:00:19,000 --> 00:00:27,000 more than 200 years after its discovery astronomers are still unveiling some of its secrets. 6 00:00:42,000 --> 00:00:47,000 Hubblecast 66: Hubble uncovers the secrets of the Ring Nebula 7 00:00:49,000 --> 00:00:53,000 Presented by Dr. J, aka Dr Joe Liske 8 00:00:56,000 --> 00:00:59,000 Hello and welcome to another episode of the Hubblecast! 9 00:00:59,000 --> 00:01:04,000 Now there are many, many beautiful and very distinctive nebulae out there, 10 00:01:04,000 --> 00:01:08,000 and Hubble has imaged many of these over the past 20 years or so. 11 00:01:10,000 --> 00:01:13,000 Now one of the most famous of these nebulae 12 00:01:13,000 --> 00:01:15,000 is an object called Messier 57, 13 00:01:15,000 --> 00:01:20,000 also known by its more popular name: the Ring Nebula. 14 00:01:21,000 --> 00:01:23,000 Fairy bright and close to Earth, 15 00:01:23,000 --> 00:01:29,000 the Ring Nebula lies just over 2 000 light-years away from us. 16 00:01:29,000 --> 00:01:32,000 It is a prominent example of a planetary nebula, 17 00:01:32,000 --> 00:01:39,000 where a dying star like our Sun has pushed its outer layers out into space. 18 00:01:43,000 --> 00:01:50,000 The nebula closely resembles the equally colourful Helix Nebula, which formed in the same way. 19 00:01:50,000 --> 00:01:53,000 Both are common observational targets 20 00:01:53,000 --> 00:01:58,000 and have been well studied by both professional and amateur astronomers for years. 21 00:02:02,000 --> 00:02:05,000 The Ring Nebula was discovered in the late 18th century 22 00:02:05,000 --> 00:02:10,000 But its true shape and structure have remained somewhat unclear... 23 00:02:10,000 --> 00:02:12,000 ...until now. 24 00:02:12,000 --> 00:02:16,000 A team of astronomers has used the NASA/ESA Hubble Space Telescope, 25 00:02:16,000 --> 00:02:18,000 alongside existing ground-based data, 26 00:02:18,000 --> 00:02:21,000 to explore the Ring Nebula in depth. 27 00:02:21,000 --> 00:02:25,000 The astronomers wanted to better understand the nebula’s structure, 28 00:02:25,000 --> 00:02:28,000 its evolution, physical conditions, and motion. 29 00:02:28,000 --> 00:02:35,000 And it turns out that the Ring Nebula is not in fact very ring-shaped after all. 30 00:02:42,000 --> 00:02:44,000 From Earth’s perspective, the Ring Nebula 31 00:02:44,000 --> 00:02:48,000 looks like a simple elliptical shape with a fuzzy boundary. 32 00:02:48,000 --> 00:02:51,000 But the new Hubble observations show clearly 33 00:02:51,000 --> 00:02:55,000 that the nebula is actually shaped more like a distorted doughnut. 34 00:02:55,000 --> 00:03:00,000 We are looking almost directly down one the poles of the structure, 35 00:03:00,000 --> 00:03:05,000 with a brightly-coloured barrel of material stretching away from us. 36 00:03:06,000 --> 00:03:10,000 Although the centre of this doughnut may look empty, 37 00:03:10,000 --> 00:03:16,000 it is full of lower-density material that stretches both towards and away from us, 38 00:03:16,000 --> 00:03:23,000 creating a shape a little like a rugby ball slotted into the doughnut’s central gap. 39 00:03:23,000 --> 00:03:31,000 The space surrounding the nebula is turbulent and full of knotty structures that formed in the nebula’s past. 40 00:03:31,000 --> 00:03:36,000 This new research disagrees with previous models of the Ring Nebula, 41 00:03:36,000 --> 00:03:41,000 which had suggested that the object has a less spherical shape. 42 00:03:46,000 --> 00:03:51,000 If we were able to rotate the Ring Nebula by 90 degrees and view it side-on, 43 00:03:51,000 --> 00:03:55,000 it has been suggested that it would actually look more like Messier 76, 44 00:03:55,000 --> 00:03:59,000 a nebula also known as the “Little Dumbbell”. 45 00:04:00,000 --> 00:04:06,000 Now these nebulae are formed of ionised gas from the atmosphere of a dying star. 46 00:04:06,000 --> 00:04:09,000 At the end of their lives, these stars throw off their outer layers 47 00:04:09,000 --> 00:04:13,000 and turn into very small, hot bodies known as white dwarfs 48 00:04:13,000 --> 00:04:16,000 the final evolutionary stage of a star like our own Sun. 49 00:04:19,000 --> 00:04:22,000 Thanks to these new observations from Hubble 50 00:04:22,000 --> 00:04:24,000 we now have a much better understanding 51 00:04:24,000 --> 00:04:27,000 of the true structure of the Ring Nebula. 52 00:04:27,000 --> 00:04:30,000 This is Dr. J, signing off for the Hubblecast. 53 00:04:30,000 --> 00:04:34,000 Once again nature has surprised us, beyond our wildest imagination. 54 00:04:36,000 --> 00:04:40,000 The Hubblecast is produced by ESA/Hubble at the European Southern Observatory in Germany. 55 00:04:41,000 --> 00:04:45,000 The Hubble mission is a project of international cooperation between NASA and the European Space Agency. 56 00:04:45,000 --> 00:04:48,000 www.spacetelescope.org 57 00:04:52,000 --> 00:04:55,000 Transcribed by ESA/Hubble. 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