Analysis Consortium released the most detailed list of stars. ESA’s Gaia mission publishes data on more than 1.8 billion stars. Astronomers from the Gaia Data Processing and Analysis Consortium released the most detailed list of stars in the Milky Way today.
The new dataset, called Gaia Early Data Release 3 (EDR3), contains detailed information (stellar position, velocity, brightness and color) on more than 1.8 billion sources known to ESA’s Gaia satellite.
This represents an increase of more than 100 million sources over the previous data release, which was made public in April 2018.
More than 1.8 billion data stars have been used to create this map of the entire sky. It shows the full brightness and color of the stars seen by ESA’s Gaia satellite and has been released as part of Gaia’s Early Data Release 3.
The bright regions represent the density of bright stars, while the darkest regions correspond to patches of sky where fewer and faster stars are seen.
The color of the image is obtained by combining the total amount of light with the amount of blue and red light recorded by Gaia in each part of the sky.
The bright horizontal structure dominating the image is the plane of our Milky Way.
It is actually a flattened disk saw edge that contains most of the stars in the Galaxy. In the middle of the image, the galactic center appears bright and full of stars. The darkest regions of the galactic plane correspond to precursor clouds of interstellar gas and dust.
Which absorb light from more distant stars. Many of these clouds hide the stellar nursery where new generation stars are currently being born. There are many circular and open clusters scattered throughout the image, as well as our own entire galaxies.
The two bright objects in the lower right of the image are the Large and Small Magellanic Clouds, two dwarf galaxies that orbit the Milky Way.
Launched on December 19, 2013, Gaia operates in an orbit around the so-called Lagrange point 2 (L2) located 1.5 million kilometers behind the Earth in a direction away from the Sun.
At L2, the gravitational forces between the Earth and the Sun are balanced, so the spacecraft remains in a stable state, making farsighted scenes essentially without the sky.
- Gaia's main goal is to measure stellar distances using the parallax method.
In this case, astronomers use the observatory to continuously scan the sky and measure the apparent change in the position of the stars over time, resulting in the movement of the Earth around the Sun.
Knowing that their distances can be calculate by small changes in the position of the stars.
Gaia tracks the changing brightness and position of stars over time in its line of sight (its so-called proper speed), and by dividing their light into spectra, it measures how fast they are moving towards or away from the sun and evaluate the chemical composition.
Equipped with 106 CCDs, equivalent to a camera with a resolution of one billion pixels, Gaia examines 50 million stars per day, completing ten measurements at a time. Representing a total of 500 million data points per day.
Gaia measures distances of hundreds of millions of objects that are thousands of light years away, with an accuracy equivalent to measuring hair thickness over 2,000 km, said UK Gaia DPAC project manager Dr. Floor said van Leeuwen, an astronomer at the Institute of Astronomy at the University of Cambridge.
These data are one of the pillars of astrophysics, allowing us to analyze our stellar neighborhood and address important questions about the origin and future of our galaxy.
The previous two launches, Gaia DR1 and Gaia DR2, featured positions of 1.6 billion stars. The Gaia EDR3 launch brings the total down to 2 billion stars.
The status of which is significantly more accurate than previous figures. This is the first two-part release; A full Gia DR3 release is planned for 2022.
The new promise of Gaia data is a treasury fund for astronomers, said Gaia project associate scientist Dr. José de Bruijnen, ESA astronomer said.
The new data includes exceptionally accurate measurements of 331,312 objects, about 92% of the stars within 100 parsecs (326 light years) of the Sun. The last census of the solar neighborhood, called the Gliese Catalog of Nearby Stars, was conducted in 1957.
It initially had only 915 objects, but in 1991 it was updated to 3,803 celestial objects. It was also limited to a distance of 82 light years: the census of Gaia reaches four times as many and has 100 times as many stars.
It also provides location, speed, and brightness measurements that are orders of magnitude more accurate than older data.
The researchers also confirmed that the solar system is accelerating its orbit around the galaxy. Using the observed targets of extremely distant galaxies, the velocity of our solar system has been measured to change every second at 0.23 nm / sec.
Due to this small acceleration, the path of the solar system deviates by the diameter of one atom per second, adding up to about 115 km in a year.
The acceleration measured by Gaia shows good agreement with theoretical expectations and provides the first measure of the curvature of the solar system's orbit around the galaxy in the history of optical astronomy.
The team also sees evidence of the Milky Way's past by looking at the stars in the direction of the galaxy's 'anticenter'.
It is exactly in the opposite direction from the center of the galaxy to the sky. Computer models hypothesized that the Milky Way's disk would enlarge over time as new stars were born.
The new data allows scientists to see remnants of 10-billion-year-old ancient disks and thus establish a range smaller than the current size of the Milky Way disk.
The data from these peripheral regions also reinforce the evidence for another major event in the Galaxy's more recent times.
The data shows that the outer regions of the disk have a slow-moving wire component above the plane of our galaxy moving down toward the plane, and a fast-moving wire component below the plane above. In direction to
This extraordinary pattern was not anticipated before. This may be the result of a near-collision between the Milky Way and the Sagittarius dwarf galaxy that occurred in our galaxy's recent past.
Disc stars have different movement patterns than we used to believe, said Dr. Teresa Antoja, an astronomer at the University of Barcelona.
"Although the role of the Sagittarius dwarf galaxy is still debated in some quarters, it may be a good candidate for all of these disturbances, as some simulations by other authors show." The new Gaia data also reconstructs the Milky Way's two largest companion galaxies.
The Small and Large Magellanic Clouds, allowing astronomers to see their different stellar populations. After measuring the motion of the stars in the large Magellanic cloud more precisely than before, the team clearly shows that the galaxy has a spiral structure.
The data also resolves a stream of stars that are being ejected from the small Magellanic cloud, and hints at previously undiscovered structures on the outskirts of both galaxies.
Gaia EDR3 is the result of a great effort on the part of everyone involved in the Gaia mission, said Gaia project scientist Dr. Timo Priesti, ESA astronomer said.
This is an exceptionally rich data set, and I look forward to the many discoveries that astronomers around the world will make with this resource and we haven't done it yet.
And more great data will follow as Gaia continues to measure from orbit. These attractive results come from a set of documents that demonstrate the quality of the EDR3 version.