1 00:00:02,000 --> 00:00:06,000 Astronomers using ESO’s world-leading HARPS instrument 2 00:00:06,000 --> 00:00:10,000 have discovered a planetary system containing at least five planets, 3 00:00:10,000 --> 00:00:14,000 orbiting the Sun-like star HD 10180. 4 00:00:14,000 --> 00:00:18,000 The researchers also believe the system has two other planets, 5 00:00:18,000 --> 00:00:21,000 one of which would have the lowest mass ever found, 6 00:00:21,000 --> 00:00:26,000 making the system similar to our own Solar System in terms of the number of planets. 7 00:00:26,000 --> 00:00:29,000 Furthermore, the scientists find that the location of the planets 8 00:00:29,000 --> 00:00:34,000 follows a regular pattern, as also seen in our own Solar System. 9 00:00:39,000 --> 00:00:41,000 This is the ESOcast! 10 00:00:41,000 --> 00:00:44,000 Cutting-edge science and life behind the scenes at ESO, 11 00:00:44,000 --> 00:00:46,000 the European Southern Observatory. 12 00:00:46,000 --> 00:00:52,000 Exploring the ultimate frontier with our host Dr J, a.k.a. Dr Joe Liske. 13 00:01:00,000 --> 00:01:03,000 The team of astronomers used the HARPS spectrograph, 14 00:01:03,000 --> 00:01:07,000 attached to ESO’s 3.6-metre telescope at La Silla, Chile. 15 00:01:10,000 --> 00:01:14,000 HARPS is an instrument with unrivalled stability and great precision, 16 00:01:14,000 --> 00:01:17,000 and the world’s most successful exoplanet hunter. 17 00:01:19,000 --> 00:01:24,000 The astronomers, led by Christophe Lovis from the Geneva Observatory, 18 00:01:24,000 --> 00:01:30,000 studied the Sun-like star HD 10180 over a period of six years! 19 00:01:30,000 --> 00:01:36,000 This star is located 127 light-years away in the southern constellation Hydrus 20 00:01:36,000 --> 00:01:38,000 (“the Male Water Snake"). 21 00:01:42,000 --> 00:01:46,000 Thanks to the 190 individual HARPS measurements, 22 00:01:46,000 --> 00:01:51,000 the astronomers detected the wobbles of the star caused by five or more planets. 23 00:01:51,000 --> 00:01:56,000 The five strongest signals correspond to planets with Neptune-like masses 24 00:01:56,000 --> 00:01:59,000 — between 13 and 25 Earth masses — 25 00:01:59,000 --> 00:02:03,000 which orbit the star in between 6 to 600 days. 26 00:02:03,000 --> 00:02:08,000 The astronomers have also strong reason to believe that two other planets are present. 27 00:02:08,000 --> 00:02:13,000 One would be a Saturn-like planet orbiting in 2200 days. 28 00:02:13,000 --> 00:02:18,000 The other, having a mass of only about 1.4 times that of the Earth 29 00:02:18,000 --> 00:02:21,000 would be the least massive exoplanet ever discovered. 30 00:02:21,000 --> 00:02:25,000 This suspected planet is very close to its host star 31 00:02:25,000 --> 00:02:27,000 and so it is likely to be very hot. 32 00:02:27,000 --> 00:02:32,000 One ‘year’ on this planet lasts only 1.18 Earth-days! 33 00:02:35,000 --> 00:02:40,000 The newly discovered 'solar system' is unique in several respects. 34 00:02:40,000 --> 00:02:43,000 First of all, with at least five Neptune-like planets lying 35 00:02:43,000 --> 00:02:46,000 within a distance equivalent to the orbit of Mars, 36 00:02:46,000 --> 00:02:50,000 this system is more populated than our own Solar System in its inner region, 37 00:02:50,000 --> 00:02:53,000 and has many more massive planets there. 38 00:02:53,000 --> 00:02:58,000 Furthermore, the system probably has no Jupiter-like gas giant. 39 00:02:59,000 --> 00:03:04,000 In addition, all the planets seem to have almost circular orbits. 40 00:03:04,000 --> 00:03:09,000 Dynamical studies of the new system reveal complex interactions between the planets 41 00:03:09,000 --> 00:03:12,000 and give us insights into its long-term evolution. 42 00:03:14,000 --> 00:03:18,000 Using the new discovery as well as data for other planetary systems, 43 00:03:18,000 --> 00:03:22,000 the astronomers discovered that the locations of the planets 44 00:03:22,000 --> 00:03:24,000 seem to follow a regular pattern 45 00:03:24,000 --> 00:03:28,000 — similar to the “Titius-Bode” law that exists in our Solar System. 46 00:03:28,000 --> 00:03:32,000 This could be a general signature of how planetary systems form. 47 00:03:36,000 --> 00:03:40,000 Another important result is that all very massive planetary systems 48 00:03:40,000 --> 00:03:43,000 are found around massive and metal-rich stars, 49 00:03:43,000 --> 00:03:49,000 while the four lowest-mass systems are found around lower-mass and metal-poor stars. 50 00:03:49,000 --> 00:03:53,000 These properties confirm current theoretical models. 51 00:03:53,000 --> 00:03:56,000 There is no doubt that this remarkable discovery highlights the fact 52 00:03:56,000 --> 00:04:00,000 that we are now entering a new era in exoplanet science: 53 00:04:00,000 --> 00:04:06,000 the study of complex planetary systems and not just of individual planets! 54 00:04:07,000 --> 00:04:13,000 And with HARPS, European astronomers will be a driving force behind this transition. 55 00:04:17,000 --> 00:04:21,000 ESOcast is produced by ESO, the European Southern Observatory. 56 00:04:21,000 --> 00:04:25,000 ESO, the European Southern Observatory, is the pre-eminent intergovernmental science and technology organisation in astronomy, 57 00:04:25,000 --> 00:04:28,000 designing, constructing and operating the world’s most advanced ground-based telescopes. 58 00:04:31,000 --> 00:04:36,000 Transcription by ESO ; translation by — 59 00:04:37,000 --> 00:04:41,000 Now that you've caught up with ESO, 60 00:04:42,000 --> 00:04:46,000 head 'out of this world' with Hubble. 61 00:04:48,000 --> 00:04:55,000 The Hubblecast highlights the latest discoveries of the world´s most recognized and prized space observatory, 62 00:04:57,000 --> 00:05:01,000 the NASA/ESA Hubble Space Telescope