Gaia is a survey mission launched in 2013 on a Soyuz-STB/Fregat-MT launch vehicle from the European Spaceport in Kourou, French Guiana. It is currently surveying our Milky Way galaxy and beyond, is also known as the (European Space Agency) ESA’s billion-star surveyor, and is on its way to creating a three-dimensional map of the galaxy. The idea is to search for the origin, structure, and evolution of our galaxy. The surveyor is 10m wide and contains a billion-pixel camera which allows capturing our (at least local) universe in fine detail.
On June 13, 2022, the ESA published their third data release, which means that they have released all the data Gaia collected from July 2014 to May 2017, analyzed it, and have now released it to the public. Just like the previous releases, it contains stars, quasars, variable objects, asteroids, and many other things which are found in space.
Among the 1.4 billion stars, this data release also mentions the detection of starquakes, a phenomenon known, but never witnessed before. Usually, radial oscillations are seen in stars which cause them to shrink or swell, but the overall shape does not change. Starquakes are different from these oscillations, more analogous to tsunamis, such that they change the shape of the underlying stars by ablating them in either direction. Gaia found 1000s of stars with starquakes in this data release. This kind of study falls under asteroseismology, a branch of astrophysics that studies the seismic activities in stars.
In addition, Gaia also recovered the DNA of stars in our galaxy and was able to tell whether any of these came from other galaxies. This star DNA is based on the chemical composition of stars rather than genetic material. The stars in the early universe mainly contained only hydrogen and helium, whereas the most recent ones contain heavy elements. Moreover, one very important part of this mission is that it keeps looking at various stars multiple times, therefore allowing us to detect any changes in those stars over time, which is usually a hard task with other facilities due to the time and cost involved. Let us hope for many more years of data to come from this unique but wonderful mission. Please watch the video below to know more details about recent discoveries by this mission.
Source: ESA Gaia, Gaia-DR3
