Search

    WEBMAIL    |    Intranet    |    Site Map

 

 

Gaia releases the most detailed Milky Way survey to date

on 17 June 2022

ESA’s Gaia mission released its new treasure trove of data about our home galaxy. Astronomers describe strange ‘starquakes’, stellar DNA, asymmetric motions and other fascinating insights in this most detailed Milky Way survey to date.

Gaia is ESA’s mission to create the most accurate and complete multi-dimensional map of the Milky Way. This allows astronomers to reconstruct our home galaxy’s structure and past evolution over billions of years, and to better understand the lifecycle of stars and our place in the Universe. 

Gaia’s data release 3 contains new and improved details for almost two billion stars in our galaxy. The catalogue includes new information including chemical compositions, stellar temperatures, colours, masses, ages, and the speed at which stars move towards or away from us (radial velocity). Much of this information was revealed by the newly released spectroscopy data, a technique in which the starlight is split into its constituent colours (like a rainbow). The data also includes special subsets of stars, like those that change brightness over time.

Also new in this data set is the largest catalogue yet of binary stars, thousands of Solar System objects such as asteroids and moons of planets, and millions of galaxies and quasars outside the Milky Way. 

One of the most surprising discoveries coming out of the new data is that Gaia is able to detect starquakes – tiny motions on the surface of a star – that change the shapes of stars, something the observatory was not originally built for.

Previously, Gaia already found radial oscillations that cause stars to swell and shrink periodically, while keeping their spherical shape. But Gaia has now also spotted other vibrations that are more like large-scale tsunamis. These nonradial oscillations change the global shape of a star and are therefore harder to detect.

What stars are made of can tell us about their birthplace and their journey afterwards, and therefore about the history of the Milky Way. With the latest data release, Gaia is revealing the largest chemical map of the galaxy coupled to 3D motions, from our solar neigbourhood to smaller galaxies surrounding ours.

More details here.

Image credit: ESA/Gaia/DPAC; CC BY-SA 3.0 IGO, CC BY-SA 3.0 IGO