The European Space Agency has released the world’s most exhaustive star catalog, pinpointing the positions of nearly 1.7 billion stars.
Today’s release, based on 22 months’ worth of data from ESA’s Gaia sky-mapping satellite, follows up on an initial version of the catalog that was released in 2016. This second release adds readings from the period between September 2015 and May 2016.
The Gaia mission’s second data release was presented at the ILA Berlin Air and Space Show in Germany. In addition to the positional data, the new catalog lists parallax and velocity readings for 1.3 billion stars — making it easy for astronomers to plot their distances and motions with respect to Earth.
“The observations collected by Gaia are redefining the foundations of astronomy,” Günther Hasinger, ESA’s director of science, said in a news release.
Astronomy fans agreed, and gushed over the treasure trove on Twitter:
https://twitter.com/nattyover/status/989150315713847296
https://twitter.com/jobovy/status/989155568374906880
https://twitter.com/Nattie_G_/status/989202455383568384
https://twitter.com/esa/status/989089021350596609
https://twitter.com/coreyspowell/status/989138966149500928
https://twitter.com/ESAGaia/status/989079122608558081
Gaia was launched in 2013 and uses two telescopes to track stars and other celestial objects from the vicinity of a gravitational balance point known as Sun-Earth L2. To determine distances and motions, Gaia tracks apparent shifts in the position of objects against their cosmic background as the truck-sized spacecraft moves around the sun.
In addition to mapping stars, Gaia tracks asteroids in our solar system and quasars far beyond our galaxy. Today’s data release provides positional data on 14,000 asteroids and about half a million quasars. Future releases are expected to add to all those tallies.
The $900 million (€740 million) primary mapping mission is due to last until 2019.
Scientific papers describing the data contained in the release and their validation process will appear in a special issue of Astronomy & Astrophysics. A series of 360-degree videos and other virtual-reality visualization resources are available at http://sci.esa.int/gaia-vr.