1 00:00:01,000 --> 00:00:08,000 Images from ESO’s Very Large Telescope and the NASA/ESA Hubble Space Telescope have revealed 2 00:00:08,000 --> 00:00:17,000 unique and totally unexpected structures in the dusty disc around the star AU Microscopii. 3 00:00:18,000 --> 00:00:28,000 These fast-moving wave-like dust features are unlike anything ever observed, or even predicted, before now. 4 00:00:33,000 --> 00:00:44,000 This is the ESOcast! Cutting-edge science and life behind the scenes at ESO, the European Southern Observatory. 5 00:00:50,000 --> 00:01:00,000 AU Microscopii, or AU Mic for short, is a young nearby star surrounded by a large disc of dust. 6 00:01:00,000 --> 00:01:06,000 Studies of such discs can provide valuable clues about how planets form. 7 00:01:08,000 --> 00:01:16,000 Astronomers have been searching AU Mic’s disc for any signs of clumpy or warped features for years. 8 00:01:17,000 --> 00:01:22,000 Such features might give away the location of possible planets. 9 00:01:25,000 --> 00:01:32,000 For their search, astronomers have now used the powerful new imaging capabilities of ESO’s 10 00:01:32,000 --> 00:01:36,000 SPHERE instrument, mounted on the Very Large Telescope. 11 00:01:37,000 --> 00:01:41,000 And they discovered something completely unexpected. 12 00:01:59,000 --> 00:02:06,000 Five wave-like arches at different distances from the star showed up in the new image. 13 00:02:09,000 --> 00:02:18,000 The astronomers compared the SPHERE data with images of the disc taken by Hubble in 2010 and 2011. 14 00:02:18,000 --> 00:02:25,000 The comparison of the data showed that these ripples were moving — and moving very fast! 15 00:02:26,000 --> 00:02:34,000 At least three of the features are moving so fast that they are escaping from the gravitational pull of the star. 16 00:02:34,000 --> 00:02:39,000 Such high speeds rule out the possibility that these are conventional disc features 17 00:02:39,000 --> 00:02:45,000 caused by planets disturbing material in the disc while orbiting the star. 18 00:02:45,000 --> 00:02:52,000 There must have been something else involved to speed up the ripples and make them move so quickly. 19 00:02:52,000 --> 00:02:57,000 This means that they are a sign of something truly unusual. 20 00:02:59,000 --> 00:03:04,000 One explanation for the strange structure could be flares from the star. 21 00:03:05,000 --> 00:03:11,000 AU Mic often lets off huge bursts of energy from its surface. 22 00:03:13,000 --> 00:03:17,000 One of these flares could perhaps have violently stripped away 23 00:03:17,000 --> 00:03:21,000 material from one of the planets — if there are any planets. 24 00:03:22,000 --> 00:03:28,000 This material could now be propagating through the disc, propelled by the force of the flare. 25 00:03:30,000 --> 00:03:35,000 To get the final answer to the nature of these features astronomers will need 26 00:03:35,000 --> 00:03:40,000 additional observations made from the ground and from space. 27 00:03:41,000 --> 00:03:50,000 But, for now, these curious features remain a big surprise and an unsolved mystery. 28 00:03:52,000 --> 00:03:56,000 Transcription by ESO; translation by —