This week saw the release of a treasure trove of data from the European Space Agency’s (ESA) Gaia mission, a space-based observatory that is mapping out the Milky Way in three dimensions. The newly released data includes half a million new stars and details about more than 150,000 asteroids within our solar system.
The overall aim of the Gaia mission is to create a full 3D map of our galaxy that includes not only stars, but also other objects like planets, comets, asteroids, and more. The mission was launched in 2013 and the data it collected is released in batches every few years, with previous releases including data on topics like the positions of over 1.8 billion stars.
The new data release fills in some gaps from previous releases, particularly in areas of the sky that are densely packed with stars — such as the Omega Centauri globular cluster, shown above. The new view of this cluster shows 10 times as many stars as the previous data, with a total of 526,587 new stars identified.
“In Omega Centauri, we discovered over half a million new stars Gaia hadn’t seen before – from just one cluster!” said lead author Katja Weingrill of Germany’s Leibniz-Institute for Astrophysics Potsdam in a statement. Gaia will now be used to study more clusters and to collect more detailed information on them.
Another key find in this release is a large number of gravitational lenses. This effect occurs when a massive object such as a galaxy cluster warps space-time, making light from more distant objects bend and acting like a magnifying glass. This allows researchers to see much more distant objects than they would be able to otherwise.
“Gaia is a real lens-seeker,” said co-author Christine Ducourant of France’s Laboratoire d’Astrophysique de Bordeaux. “Thanks to Gaia, we’ve found that some of the objects we see aren’t simply stars, even though they look like them. They’re actually really distant lensed quasars – extremely bright, energetic galactic cores powered by black holes. We now present 381 solid candidates for lensed quasars, including 50 that we deem highly likely — a gold mine for cosmologists, and the largest set of candidates ever released at once.”
Gaia wasn’t particularly designed to search for this kind of cosmology data, but it is turning up such findings as a bonus in its survey. “Although its key focus is as a star surveyor, Gaia is exploring everything from the rocky bodies of the solar system to multiply imaged quasars lying billions of light-years away, far beyond the edges of the Milky Way,” said Timo Prusti, Project Scientist for Gaia at ESA. “The mission is providing a truly unique insight into the universe and the objects within it, and we’re really making the most of its broad, all-sky perspective on the skies around us.”
