Free Astronomy Magazine July-August 2019

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 Internet Service Provider Aruba S.p.A. Via San Clemente, 53 24036 Ponte San Pietro - BG - 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 copy- right law. A single copy of the materi- als available through this course may be made, solely for personal, noncom- mercial use. Users may not distribute such copies to others, whether or not in electronic form, whether or not for a charge or other consideration, with- out prior written consent of the copy- right holder of the materials. The publisher makes available itself with having rights for possible not charac- terized iconographic sources. Advertising - Administration Astro Publishing di Pirlo L. Via Bonomelli, 106 25049 Iseo - BS - ITALY email ASTROFILO l’ July-August 2019 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 4 30 32 36 40 50 years ago, we walked on the Moon (Part Two of Two) Let us continue and complete our contribution to the celebrations of the fiftieth anniversary of the conquest of the Moon, the first part of which was published in the May-June issue. The goal remains to highlight the reasons why NASA chose specific sites for the six human landings and the importance... Heavy metal planet fragment survives destruction from dead star A fragment of a planet that has survived the death of its star has been discovered in a disc of debris formed from destroyed planets which the star ultimately consumes. The discovery was made by a group of astronomers led by the University of Warwick and involving research staff from the IAC and ULL... Hubble captures rare active asteroid Thanks to an impressive collaboration bringing together data from ground-based telescopes, all-sky sur- veys and space-based facilities — including the Hubble Space Telescope — a rare self-destructing asteroid called 6478 Gault has been observed. Clear images from the NASA/ESA Hubble Space Telescope have... Pinpointing Gaia to map the Milky Way Gaia, operated by the European Space Agency (ESA), surveys the sky from orbit to create the largest, most precise, three-dimensional map of our Galaxy. One year ago, the Gaia mission produced its much- awaited second data release, which included high-precision measurements — positions, distance and... A system of globular clusters in the disc of a galaxy Globular clusters are clusters of between a hundred thousand and a million stars, whose components have all roughly the same age, and have similar chemical composition. They are very old objects, formed some 11,500 million years ago, 2,300 million years after the Big Bang. These clusters are... Radio emissions from dust particles in MACS0416_Y1 Researchers have detected a radio signal from abundant interstellar dust in MACS0416_Y1, a galaxy 13.2 billion light-years away in the constellation Eridanus. Standard models can’t explain this much dust in a galaxy this young, forcing us to rethink the history of star formation. Researchers now think... HiPERCAM reveals new details about the oldest stars in the Milky Way An international team, led by a researcher from the Universitat Politècnica de Catalunya - BarcelonaTech (UPC) and the Institute of Space Studies of Catalonia (IEEC), has measured for the first time the stellar parameters of a very old kind of stars, known as cool subdwarf stars, in our Galaxy, the Milky Way... Hubble assembles wide view of the distant Universe Astronomers have put together the largest and most comprehensive “history book” of galaxies into one single image, using 16 years’ worth of observations from NASA’s Hubble Space Telescope. The deep-sky mosaic, created from nearly 7,500 individual exposures, provides a wide portrait of the distant Universe... GRAVITY breaks new ground in exoplanet imaging The GRAVITY instrument on ESO’s Very Large Telescope Interferometer (VLTI) has made the first direct observation of an exoplanet using optical interferometry. This method revealed a complex exoplanetary atmosphere with clouds of iron and silicates swirling in a planet-wide storm. The technique presents... Disparity in Hubble Constant calculations is not a fluke Astronomers using NASA’s Hubble Space Telescope say they have crossed an important threshold in re- vealing a discrepancy between the two key techniques for measuring the universe’s expansion rate. The recent study strengthens the case that new theories may be needed to explain the forces that have... 44 46 48 50 54