1 00:00:00,000 --> 00:00:06,000 The NASA/ESA Hubble Space Telescope has recently revealed magnificent sections of the Veil Nebula – 2 00:00:06,000 --> 00:00:11,000 the shattered remains of a supernova that exploded some 5-10,000 years ago. 3 00:00:11,000 --> 00:00:18,000 The new Hubble images provide beautiful views of the delicate, wispy structure resulting from this cosmic cataclysm. 4 00:00:35,000 --> 00:00:37,000 This is the Hubblecast! 5 00:00:37,000 --> 00:00:47,000 News and Images from the NASA/ESA Hubble Space Telescope. Travelling through time and space with our host Doctor J a.k.a. Dr Joe Liske. 6 00:00:48,000 --> 00:00:50,000 Welcome to the Hubblecast! 7 00:00:50,000 --> 00:00:56,000 Today we will take a closer look at one of the most violent events in the Universe – a supernova explosion. 8 00:00:56,000 --> 00:01:02,000 It is the debris from one of these cosmic explosions that we can see with unprecedented detail 9 00:01:02,000 --> 00:01:05,000 in these brand new images from the Hubble Space Telescope. 10 00:01:05,000 --> 00:01:12,000 Although we don’t usually think about it, the stars twinkling in the night sky do not shine forever. 11 00:01:12,000 --> 00:01:20,000 How long a star lives depends on how big and heavy it is. The bigger a star, the shorter its life. 12 00:01:20,000 --> 00:01:24,000 Now a star shines because of the nuclear fire burning at its centre. 13 00:01:24,000 --> 00:01:30,000 And when a star significantly larger than our Sun runs out of fuel for this fire, 14 00:01:30,000 --> 00:01:37,000 it first collapses and then blows itself apart in a gigantic explosion that we call a supernova 15 00:01:37,000 --> 00:01:47,000 A supernova releases so much light that it can outshine all of the stars of an entire galaxy put together. 16 00:01:47,000 --> 00:01:51,000 The explosion sweeps out a huge bubble in its surroundings, 17 00:01:51,000 --> 00:01:58,000 and at the fringe of this bubble we find the actual debris from the star as well the material that has been swept up by the blast wave. 18 00:01:58,000 --> 00:02:08,000 It is this glowing, brightly-coloured shell of gas that we see as a nebula and that astronomers refer to as a ‘supernove remnant’. 19 00:02:08,000 --> 00:02:15,000 Now the remnant can remain visible for a very long time after the actual explosion itself has faded away. 20 00:02:17,000 --> 00:02:24,000 Astronomers have pointed Hubble towards the constellation of Cygnus to observe the Veil Nebula in the wing of the Swan. 21 00:02:24,000 --> 00:02:35,000 Located at a distance of 1,500 light-years from Earth, the Veil Nebula, which is also known as Cygnus Loop, is one of the most spectacular supernova remnants in the sky. 22 00:02:35,000 --> 00:02:40,000 The entire shell spans about 3 degrees, corresponding to about 6 full moons. 23 00:03:01,000 --> 00:03:05,000 One of the most remarkable parts of the remnant is the so-called Witch’s Broom Nebula. 24 00:03:05,000 --> 00:03:15,000 The bright blue star – dubbed 52 Cygni is unrelated to the supernova explosion – it can be observed with the naked eye on a clear summer’s night. 25 00:03:15,000 --> 00:03:20,000 The small regions captured in the new Hubble images provide stunning close-ups of the Veil. 26 00:03:20,000 --> 00:03:27,000 Fascinating smoke-like wisps of gas are all that remain visible of what was once a Milky Way star. 27 00:03:28,000 --> 00:03:34,000 Scientists estimate that the supernova explosion occurred some 5-10,000 years ago. 28 00:03:34,000 --> 00:03:41,000 Now what that means is that it could have been witnessed and recorded by ancient civilizations. 29 00:03:41,000 --> 00:03:47,000 What they would have seen is a star increasing its brightness roughly the brightness of the crescent Moon. 30 00:03:50,000 --> 00:03:56,000 The intertwined rope-like filaments of gas in the Veil Nebula result from the enormous energy released 31 00:03:56,000 --> 00:04:03,000 as the fast-moving debris from the explosion ploughs into its surroundings and creates a shock front. 32 00:04:04,000 --> 00:04:12,000 This shock, driven by debris moving at 600,000 kilometres per hour, heats the gas to millions of degrees. 33 00:04:12,000 --> 00:04:18,000 It is the subsequent cooling of this material that produces the brilliantly coloured glows. 34 00:04:18,000 --> 00:04:25,000 The Hubble images of the Veil Nebula are striking examples of how processes that take place hundreds of light-years away 35 00:04:25,000 --> 00:04:29,000 can sometimes resemble effects we see around us in our daily life. 36 00:04:29,000 --> 00:04:40,000 There are similarities with the patterns formed by the interplay of light and shadow on the bottom of a swimming pool, rising smoke or a wispy cirrus clouds. 37 00:04:40,000 --> 00:04:44,000 So why are astronomers interested in studying supernovae and their remnants? 38 00:04:44,000 --> 00:04:50,000 The reason is that they are extremely important for understanding the history of our own Milky Way. 39 00:04:50,000 --> 00:04:56,000 Although only a few stars per century in our Galaxy end their lives in this spectacular way, 40 00:04:56,000 --> 00:05:03,000 these explosions are more or less directly responsible for creating all the elements in our Universe that are heavier than iron. 41 00:05:03,000 --> 00:05:12,000 or example, all the copper, mercury, gold, iodine and lead that we see on Earth around us here today, 42 00:05:12,000 --> 00:05:17,000 were forged in these violent explosions billions of years ago. 43 00:05:17,000 --> 00:05:24,000 The expanding shells of supernova remnants eventually mixed with other material in the Milky Way, 44 00:05:24,000 --> 00:05:31,000 and this became the raw material for the next generation of stars and planets, including our own Solar System. 45 00:05:32,000 --> 00:05:40,000 So the chemical elements that constitute the planets, the Earth, the plants and animals around us – and indeed our very selves – 46 00:05:40,000 --> 00:05:45,000 were built deep inside ancient stars and in the supernova explosions. 47 00:05:45,000 --> 00:05:51,000 So the green in the grass and the red of our blood are in fact the colours of stardust. 48 00:05:52,000 --> 00:05:55,000 This is Dr J signing off for the Hubblecast. 49 00:05:55,000 --> 00:05:59,000 Once again nature has surprised us beyond our wildest imagination … 50 00:06:00,000 --> 00:06:05,000 Hubblecast is produced by ESA/Hubble at the European Southern Observatory in Germany. 51 00:06:05,000 --> 00:06:09,000 The Hubble mission is a project of international cooperation between NASA and the European Space Agency.