1 00:00:00,630 --> 00:00:04,314 The NASA / ESA Hubble Space Telescope has discovered an extra-solar planet 2 00:00:04,315 --> 00:00:08,084 for the first time using direct visible light imaging. 3 00:00:08,085 --> 00:00:11,470 The strange world is far-flung from its parent star, 4 00:00:11,505 --> 00:00:14,821 is surrounded by a colossal belt of gas and dust 5 00:00:14,856 --> 00:00:19,172 and may even have rings more impressive than Saturn's. 6 00:00:35,559 --> 00:00:37,351 This is the Hubblecast. 7 00:00:37,352 --> 00:00:40,815 News and images from the NASA / ESA Hubble Space Telescope. 8 00:00:40,816 --> 00:00:44,367 Travelling through time and space with our host, Dr. J 9 00:00:44,368 --> 00:00:47,767 EPISODE 22: Hubble directly observes planet orbiting Fomalhaut a.k.a. Dr. Joe Liske. 10 00:00:47,768 --> 00:00:50,596 Hello and welcome to another episode of the Hubblecast. 11 00:00:51,298 --> 00:00:53,767 Our favourite orbiting observatory has been busy 12 00:00:53,768 --> 00:00:57,061 helping astronomers to study extra-solar planets: 13 00:00:57,062 --> 00:01:00,602 those enigmatic worlds orbiting stars other than our Sun. 14 00:01:00,603 --> 00:01:04,076 And, what you know, Hubble has done it again. 15 00:01:04,077 --> 00:01:06,752 It has delivered yet another stunning breakthrough 16 00:01:06,788 --> 00:01:10,623 when it turned its gaze on the star Fomalhaut. 17 00:01:11,803 --> 00:01:14,619 Fomalhaut is visible from the southern hemisphere 18 00:01:14,620 --> 00:01:17,892 and it's one of the brightest stars in our night sky. 19 00:01:17,893 --> 00:01:21,797 Lying around 25 light-years distant, it's also relatively close. 20 00:01:23,103 --> 00:01:27,551 Fomalhaut is much hotter than our Sun and 15 times as bright. 21 00:01:27,552 --> 00:01:33,702 It's blazing through hydrogen at such a furious rate that it'll burn out in only one billion years: 22 00:01:33,703 --> 00:01:36,728 10% the lifespan of our star. 23 00:01:38,342 --> 00:01:43,645 But perhaps its most interesting feature is the large disc of gas that surrounds it, 24 00:01:43,680 --> 00:01:46,044 looking like a life belt. 25 00:01:46,045 --> 00:01:50,227 It's this ring which first sparked the attention of astronomers. 26 00:01:50,262 --> 00:01:53,749 It isn't centered on Fomalhaut quite as predicted 27 00:01:53,750 --> 00:01:58,969 hinting that the gravity of another body, perhaps a planet, is pulling it out of shape. 28 00:02:01,063 --> 00:02:05,418 And so, Hubble was called upon to solve the mystery of the misshapen disc. 29 00:02:05,419 --> 00:02:10,757 And, lo and behold, the image produced by Hubble actually does show a planet. 30 00:02:10,758 --> 00:02:13,769 It orbits Fomalhaut at an enormous distance, 31 00:02:13,770 --> 00:02:17,319 about 10 times the distance between Saturn and the Sun. 32 00:02:17,720 --> 00:02:21,527 In honour of its parent star, astronomers have given this planet 33 00:02:21,562 --> 00:02:28,371 the extremely catchy and very imaginative name, Fomalhaut... b. 34 00:02:29,556 --> 00:02:32,734 Planets around other stars have been detected before. 35 00:02:32,735 --> 00:02:35,468 But usually indirectly by looking for clues, 36 00:02:35,503 --> 00:02:39,625 like the wobbling motion of a star as a planet orbits it 37 00:02:39,626 --> 00:02:43,416 or a star getting dimmer as a planet passes in front of it. 38 00:02:44,511 --> 00:02:48,970 This time, Hubble has given us a rare direct image of an extra-solar planet. 39 00:02:49,005 --> 00:02:54,556 And what's more, the first in visible light, the type our eyes naturally see. 40 00:02:55,544 --> 00:02:59,228 Amazingly, Hubble has managed to take a snapshot of this planet 41 00:02:59,229 --> 00:03:03,485 not just once but twice, with almost two years in between. 42 00:03:03,744 --> 00:03:08,319 Being able to actually see the same dot of light moving around the central star 43 00:03:08,320 --> 00:03:11,788 is a very clear sign that this object really is in orbit, 44 00:03:11,789 --> 00:03:15,329 and that it's not just something that happens to lie along the line of sight. 45 00:03:15,330 --> 00:03:17,834 Now astronomers have calculated that it takes this planet 46 00:03:17,835 --> 00:03:21,840 about 872 Earth-years to complete one orbit. 47 00:03:22,368 --> 00:03:26,461 Now taking an image of an extra-solar planet is a very tricky business. 48 00:03:26,462 --> 00:03:30,280 Fomalhaut is one of the brightest stars in the night sky. 49 00:03:30,281 --> 00:03:34,451 By comparison, the planet is just a very tiny dot of light. 50 00:03:34,452 --> 00:03:37,237 Now being able to see that light was only made possible 51 00:03:37,238 --> 00:03:40,322 once most of the light from the star was blocked 52 00:03:40,323 --> 00:03:43,627 using an instrument called a coronagraph. 53 00:03:44,548 --> 00:03:49,225 So Hubble managed to peer through the glare and view the planet directly. 54 00:03:49,226 --> 00:03:53,226 Then clues were gathered to paint a picture of this exotic world. 55 00:03:53,227 --> 00:03:58,849 The shape of the disc hints that the planet is at most three times the mass of Jupiter. 56 00:03:59,617 --> 00:04:02,268 And the observation showed that Fomalhaut b 57 00:04:02,269 --> 00:04:06,015 is much brighter than expected for an object of its size. 58 00:04:06,016 --> 00:04:09,877 It could have an enormous ring system, much larger than Saturn's, 59 00:04:09,878 --> 00:04:12,688 reflecting starlight in all directions. 60 00:04:13,103 --> 00:04:17,501 One day the material in this rings may eve coalesce to form moons. 61 00:04:19,144 --> 00:04:23,097 Unfortunately, we won't be visiting this planet any time soon. 62 00:04:23,098 --> 00:04:26,185 Although it's actually pretty close to us in a cosmic sense, 63 00:04:26,186 --> 00:04:29,689 a spaceship would still take thousands of years to get there. 64 00:04:29,690 --> 00:04:32,985 So it's lucky that we've got Hubble to give us the next best thing: 65 00:04:32,986 --> 00:04:36,102 breathtaking images and incredible science. 66 00:04:36,103 --> 00:04:38,846 This is Dr. J signing off for the Hubblecast. 67 00:04:38,847 --> 00:04:44,182 Once again, nature has surprised us beyond our wildest imagination... 68 00:04:44,183 --> 00:04:46,183 Hubblecast is produced by ESA / Hubble 69 00:04:46,184 --> 00:04:48,184 at the European Southern Observatory in Germany. 70 00:04:49,286 --> 00:04:51,286 The Hubble mission is a project of international cooperation 71 00:04:51,287 --> 00:04:53,287 between NASA and the European Space Agency.