The Gaia Galaxy Mapping Mission has detected thousands of stellar earthquakes that could provide new insights into the inner workings of stars.
The discovery is rather surprising because the spacecraft was not designed to do such work, Conny Aerts, an astronomer at the Catholic University of Leuven, Belgium, told a Space Agency press conference. European Union (ESA) on Monday 13 June.
“These vibrations cause stellar gas to rise and fall,” Aerts said. “And it changes the brightness of the star as a function of time. So it makes the stars flash in the sky.”
Gaia, launched in 2013, measures exact positions in the sky, distances from Earthvelocities and trajectories of 2 billion stars in our galaxy, the Milky Way. The mission is best known for creating the most detailed map of our galaxy. The latest data release, however, adds information on the brightness levels, masses and temperatures of half a billion stars and the detailed chemical compositions of several million of them. It is from this additional data that astronomers can glean an increasingly colorful picture of the galaxythe life and behavior of stars inside.
Related: 4 big Milky Way mysteries the next Gaia mission data dump could solve
Stellar earthquakes were discovered in a subset of observations that focus on the distribution of variable stars in the Milky Way galaxy, they are stars that change in brightness over time.
“Blinking stars offer astronomers a very powerful tool to study their internal physics and chemistry,” Aerts said. “It’s like earthquakes on Earth. Seismologists like earthquakes if they are not too violent, because they allow us to understand what is happening inside our planet. And astroseismologists do the same, but for the stars.”
The June 13 Gaia data release also contains the largest ever compiled data set of binary star systems in our galaxy, i.e. pairs of stars (or stars and black holes) that orbit each other.
“This is something the astronomical community is excited about because binary stars, for example, are the only way to directly measure the mass of stars,” said Anthony Brown, an astronomer at Leiden University in the Netherlands. and the president of the Gaia Data Processing and Analysis Consortium (DPAC) which prepared the data for public release, told Space.com. “We can also detect really interesting things like stars that have neutron stars or black holes as companions.”
This new dataset contains 40 times more binary star systems than previously known and studied, said Antonella Vallenari, astronomer at the Observatory of Padova and vice-president of DPAC, during the press conference.
Brown described the new data release as “a supermarket of astronomical data” that astronomers around the world will visit regularly over the years and decades to come. Another addition to the Data Supermarket’s lineup are measurements of so-called radial velocities, the speeds at which stars move away from or approach Gaia, from more than 30 million stars. As the stellar movements follow the rules of physicsastronomers can model their trajectories in the past and the future, reconstruct the evolution of the Milky Way over the eternities and in three dimensions.
“We ingested 940 billion observations out of 2 billion [light] sources to produce the data release,” Brown said. “What we’re releasing today consists of 10 terabytes of compressed data, which is the richest set of astronomical data ever released.”
Image 1 of 4
But Gaia doesn’t just see the stars of the Milky Way. He also observes objects in our solar system. The new version will therefore make a huge contribution to the search for asteroids because it contains data on the chemical compositions of 60,000 space rocks in the solar system. Previously, only 4,500 asteroids had their chemical composition known, ESA’s Gaia project scientist Jos de Bruijne told Space.com.
“It’s a 13-fold increase,” De Bruijne said.
The dataset also contains precise information about the orbits of these asteroids, allowing astronomers to spot potential dangers to Earth, but also to analyze asteroid families based on their chemical compositions and track them back to Earth. to their origins.
DPAC is already hard at work on the next batch of Gaia data, which is expected to contain a huge catalog of newly discovered data. exoplanets. The mission will continue to scan the skies until 2025, when it will run out of fuel.