Free Astronomy Magazine September-October 2015

Editor in chief Michele Ferrara Scientific advisor Prof. Enrico Maria Corsini Publisher Astro Publishing di Pirlo L. Via Bonomelli, 106 25049 Iseo - BS - ITALY email info@astropublishing.com Internet Service Provider Aruba S.p.A. Loc. Palazzetto, 4 52011 Bibbiena - AR - ITALY Copyright All material in this magazine is, unless otherwise stated, property of Astro Publishing di Pirlo L. or included with permission of its author. Reproduction or retransmission of the materials, in whole or in part, in any manner, with- out the prior written consent of the copyright holder, is a violation of copyright law. A single copy of the materials available through this course may be made, solely for personal, non- commercial use. Users may not distrib- ute such copies to others, whether or not in electronic form, whether or not for a charge or other consideration, without prior written consent of the copyright holder of the materials. The publisher makes available itself with having rights for possible not characterized iconographic sources. Advertising - Administration Astro Publishing di Pirlo L. Via Bonomelli, 106 25049 Iseo - BS - ITALY email admin@astropublishing.com ASTROFILO l’ September-October 2015 BI-MONTHLY MAGAZINE OF SCIENTIFIC AND TECHNICAL INFORMATION FREELY AVAILABLE THROUGH THE INTERNET English edition of the magazine S U M M A R Y Astonishing Pluto A faultless mission, that of New Horizons: after a journey of nine and a half years it finally made its rendezvous with Pluto one minute earlier than predicted and performed its task in the best of ways, revealing a world remarkably more lively and varied than we could have imagined. In these pages... 4 Kepler-452b is not a new Earth Discovering a planet very similar to ours, at just the right distance from a star identical to the Sun, would be an important step forward in the search for extraterrestrial life. The rush to reach this goal could, however, make us overly optimistic and lead us to define the same as Earth a planet that in... 18 First detection of lithium from an exploding star The light chemical element lithium is one of the few elements that is predicted to have been created by the Big Bang, 13.8 billion years ago. But understanding the amounts of lithium observed in stars around us today in the Universe has given astronomers headaches. Older stars have less lithium than expected... 26 The ghost of a dying star Nicknamed the Southern Owl Nebula, this shimmering orb is a planetary nebula with a diameter of almost four light-years. Its informal name relates to its visual cousin in the northern hemisphere, the Owl Nebula. ESO 378-1, which is also catalogued as PN K 1-22 and PN G283.6+25.3, is located in the constellation of... 30 Early black hole could upend evolutionary theory An international team of astrophysicists led by Benny Trakhtenbrot, a researcher at ETH Zurich’s Insti- tute for Astronomy, discovered a gigantic black hole in an otherwise normal galaxy, using W. M. Keck Observatory’s 10-meter, Keck I telescope in Hawaii. The team, conducting a fairly routine hunt for... 32 A twin of the Sun-Jupiter system With its mass and orbital position, Jupiter has always had a decisive role in the evolution of the planetary system architecture. Not only has it fostered the birth of a planet such as Earth, but it also appears to have indirectly contributed to making it liveable. Now astronomers have discovered an almost identical... 38 Best evidence of first generation stars in the universe Astronomers have long theorised the existence of a first generation of stars — known as Population III stars — that were born out of the primordial material from the Big Bang. The name Population III arose because astronomers had already classed the stars of the Milky Way as Population I (stars like... 44 Atmosphere stripped from Neptune-sized exoplanet Astronomers using the NASA/ESA Hubble Space Telescope have discovered an immense cloud of hy- drogen dispersing from a warm, Neptune-sized planet orbiting a nearby star. The enormous gaseous tail of the planet is about 50 times the size of the parent star. A phenomenon this large has never... 46 Fossil star clusters reveal their age Using a new age-dating method and the W. M. Keck Observatory on Maunakea, an international team of astronomers have determined that ancient star clusters formed in two distinct epochs – the first 12.5 billion years ago and the second 11.5 billion years ago. Although the clusters are almost as old as the... 49 Uranus-sized planet discovered through microlensing NASA's Hubble Space Telescope and the W. M. Keck Observatory in Hawaii have made independent confirmations of an exoplanet orbiting far from its central star. The planet was discovered through a technique called gravitational microlensing. This finding opens a new piece of discovery space in the... 52