![]() ![]() A much larger asteroid sample will be compiled in Gaia’s future releases.įurther afield, Gaia closed in on the positions of half a million distant quasars, bright galaxies powered by the activity of the supermassive black holes at their cores. Gaia also observes objects in our Solar System: the second data release comprises the positions of more than 14 000 known asteroids, which allows precise determination of their orbits. It also contains the velocities along the line of sight of a subset of seven million stars, the surface temperatures of about a hundred million and the effect of interstellar dust on 87 million. The comprehensive dataset provides a wide range of topics for the astronomy community.Īs well as positions, the data include brightness information of all surveyed stars and colour measurements of nearly all, plus information on how the brightness and colour of half a million variable stars change over time. “The second Gaia data release represents a huge leap forward with respect to ESA’s Hipparcos satellite, Gaia’s predecessor and the first space mission for astrometry, which surveyed some 118 000 stars almost thirty years ago,” says Anthony Brown of Leiden University, The Netherlands.Īnthony is the chair of the Gaia Data Processing and Analysis Consortium Executive, overseeing the large collaboration of about 450 scientists and software engineers entrusted with the task of creating the Gaia catalogue from the satellite data. From the most accurate parallax measurements, about ten per cent of the total, astronomers can directly estimate distances to individual stars. The new catalogue lists the parallax and velocity across the sky, or proper motion, for more than 1.3 billion stars. With these accurate measurements it is possible to separate the parallax of stars – an apparent shift on the sky caused by Earth’s yearly orbit around the Sun – from their true movements through the Galaxy. For some of the brightest stars in the survey, the level of precision equates to Earth-bound observers being able to spot a Euro coin lying on the surface of the Moon. ![]() The new data release, which covers the period between 25 July 2014 and, pins down the positions of nearly 1.7 billion stars, and with a much greater precision. The first data release, based on just over one year of observations, was published in 2016 it contained distances and motions of two million stars. Gaia was launched in December 2013 and started science operations the following year. It demonstrates the need for long-term projects to guarantee progress in space science and technology and to implement even more daring scientific missions of the coming decades.” “Gaia is an ambitious mission that relies on a huge human collaboration to make sense of a large volume of highly complex data. ![]()
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