Tuesday, July 25, 2017

Choose Your Star: First Gaia Data Release Catalogs More than Billion Celestial Objects

Choose Your Star: First Gaia Data Release Catalogs More than Billion Celestial Objects:

Gaia's first sky map. Credit: ESA/Gaia/DPAC. Acknowledgement: A. Moitinho & M. Barros (CENTRA – University of Lisbon), on behalf of DPAC.

European Space Agency’s (ESA) Gaia satellite is on a crucial mission to create the most detailed ever 3D map of our Milky Way galaxy. Last year, the agency has published first data release provided by Gaia, which contains more than one billion stars with information about their brightness and precise position on the sky.

Finding an interesting star could be now as easy as browsing offers in order to find the best car for you on websites like Cars.com. Just like this site lists a plenitude of models from Acura to Volvo, the Gaia Data Release 1 (or DR1 for short) allows astronomers to investigate a variety of peculiar objects in the sky. While car buyers and enthusiasts can choose among a diversity of models, including Toyota Gaia, the scientific community has its own Gaia, flying in space and delivering essential astronomical data.

DR1 is a real treasure trove for astronomers studying stars in our galaxy. The catalog consists of astrometry and photometry data for over one billion sources brighter than magnitude 20.7 in the white-light photometric band G of the Gaia satellite. It is the largest all-sky survey of celestial objects to date.

ESA scientists underline that DR1 shows the density of stars measured by Gaia across the entire sky, and confirms that it has already collected superb data since the beginning of its operational life in July 2014. They note that the satellite charts the sky at precision that have never been achieved before.

In particular, DR1 contains about 1.14 billion stars with precise measurements of their position on the sky and brightness. The dataset allows astronomers to estimate distance and proper motion for over two billion stars in common with the earlier Hipparcos and Tycho-2 catalogs, based on data from ESA's Hipparcos mission. Moreover, DR1 also contains nearly 3,200 variable stars, including details about their brightness variations as well as positions and brightness of more than 2,000 quasi-stellar objects (quasars).

The promising results provided by DR1 leave the researchers hungry for more. Gaia mission scientists are convinced that subsequent data releases will revolutionize our understanding of how stars are distributed and move across the Milky Way.

“1,000 days after launch and thanks to the great work of everyone involved, we are thrilled to present this first dataset and are looking forward to the next release, which will unleash Gaia’s potential to explore our galaxy as we have never seen it before,” Fred Jansen, Gaia mission manager at ESA, said on September 14, 2016, when DR1 was published.

In general, DR1 confirms that Gaia is well on track of achieving it main goal – charting the positions, distances, and motions of one billion stars. It will be a 3D map of about one percent of the Milky Way’s stellar content – all with an unprecedented accuracy. Gaia’s second data release is currently planned for April 2018.