A map of 1.7 billion stars: RAS president congratulates Gaia scientists


"We're very curious to see what the community will do with it", says Anthony Brown, an astronomer at the Leiden Observatory in the Netherlands who chairs Gaia's data-processing collaboration. Data also includes high-precision measurement of asteroids within our Solar System and stars beyond the Milky Way Galaxy. This afternoon in Europe, the European Space Agency's (ESA) Gaia mission published its first fully 3D map of the Milky Way. Only the motions of around two million stars were captured by Gaia. The spacecraft is perched far beyond the moon's orbit, in the Lagrange-2, or L2, point, a gravitationally stable spot about 1 million miles (1.5 kilometers) away from Earth. Unlike space telescopes such as Hubble that orbit the Earth, Gaia can scan the universes without Earth obstructing a big portion of its view. Each star is measured 70 times on average. This latest release is based on 22 months of charting the sky, as part of Gaia's mission to produce the largest, most precise three-dimensional map of our Galaxy ever created.

Besides, Gaia also counted 14,000 asteroids and calculated their orbit and spotted 500,000 quasars (extremely bright and distant stars that emit a colossal energy) and bright galaxies.

Gaia's unprecedented precision allows researchers to separate the parallax of target stars - their apparent motion in the sky due to Earth's movement around the Sun - and their true, or proper, motions in the galaxy. The Gaia scientists today announced some of their preliminary findings from poring over the new data.

According to the announcement about the new data, major discoveries are expected after scientists have taken time to pore over the data.

Further data releases are planned in the coming years. This image shows all the stars' colors and brightness (top), the total density of stars (middle) and the distribution of interstellar gas and dust across the galaxy (bottom).

The unique mission is reliant on the work of United Kingdom teams at the Universities of Cambridge, Edinburgh, Leicester, Bristol, the Mullard Space Science Laboratory (MSSL) at UCL London and the Science and Technology Facilities Council's (STFC) RAL Space facility, all of whom are contributing to the processing of the vast amounts of data from Gaia, in collaboration with industrial and academic partners from across Europe. Brown told Space.com that he expects the first scientific manuscripts using the new Gaia data to be uploaded to preprint servers (such as arXiv) by tomorrow or Friday (April 26-27).

One of the new aspects of the Gaia data released today are radial velocities derived from Gaia spectra. The motion of almost 1.3 billion stars has been recorded as well as the location and brightness of 1.7 billion. These stars are situated nearly 8,000 light years away from our Earth.

" In our Milky Way, we have various households of stars that are born basically at the same time and basically with the very same chemical structure and very same qualities", Valenari discussed, including that rebuilding these households can assist researchers comprehend when and how the Milky Way was formed. However, they have always struggled to pinpoint exactly how far away they are from us, and how they move.

"Basically, you see the whole Milky Way in motion around its axis in this one image", he said.