astronomers ESA (European Space Agency) on Monday (13) released an updated three-dimensional map of the Milky Way with data on the location, trajectory and characteristics of 1.8 billion stars. It is the most accurate material about our galaxy ever made.
To do this, they relied on information gathered by the Gaia satellites sent into space in 2013 to map the Milky Way. This new cartography is the third to be released by ESA from the space probe.
According to the European Agency, this volume of data also includes new information about stars, such as their chemical composition, temperature, color, mass, age, and radial velocity — whether they are approaching or moving away from us.
Cartography also includes the largest set of data ever on binary stars, including:
- 156 thousand asteroids
- 31 planets (like Mars, Jupiter, Saturn, Uranus and Neptune).
- 1.9 million quasar
- 2.9 million galaxies
Why does it matter?
Observations of the subject cover nearly 2 billion stars, about 1% of the total number of stars in the galaxy. Such discoveries can help astronomers reconstruct the structure of the Milky Way to predict how it has evolved.
Some of the information presented today has been revealed by recently released spectroscopic data using a technique (like a rainbow) that divides starlight into the colors of its components.
The information also includes special subsets of stars, such as those that change brightness over time.
The image above shows a front view of the spiral structure of the Milky Way on the left, where most of the stars are located, interspersed with a blurry mixture of cosmic gas and dust. The disk measures about 100,000 light-years, and the Sun is halfway between the center and the periphery, according to ESA information.
On the other hand, the image shows a flat view of the disk. The data indicate that the structure is 700 light-years high embedded in a thick disk, about 3,000 light-years, and populated by older stars.
One of the findings of the data is that Gaia is able to detect stellar earthquakes: tiny motions recorded on the surface of a star that change its shape.
The subject had already encountered star oscillations that caused these celestial bodies to increase and decrease in size from time to time. The peculiarity of these oscillations is that they are radial and therefore retain their star shape, according to the Phys.org website.
New earthquakes, or large-scale near-tsunamis, are not usually radial; that is, they change the overall shape of the stars so that they are much more subtle.
“Earthquakes give us a lot of information about the stars, especially about their inner workings,” said mission collaborator Conny Aerts. “The issue is opening a gold mine for asterosismology [área da astronomia que estuda estrelas pulsantes] of massive stars “.
Identifying the chemical composition of stars — as if they were their own DNA — can provide us with information about their birthplace and future journey. So astronomers will be able to trace how our galaxy came into being.
Depending on the subject, some of the stars identified in our galaxy are made of raw materials, while others, like the Sun, are made of matter enriched by previous generations of stars.
This means that stars closer to the center and plane of our galaxy are richer in metals than stars at a greater distance.
“Our galaxy is a beautiful melting pot of stars,” said Alejandra Recio-Blanco of the French Côte d’Azur Observatoire, a member of the Gaia collaboration. “This diversity is very important because it tells the story of the creation of our galaxy.”
With information from ESA and Phys.org.