Astronomers Unveil Most Detailed 3D Map of the Milky Way to Date | Astronomy

Astronomers have unveiled the most accurate 3D map of the Milky Way to date, an achievement that promises to shed new light on how the galaxy works and the mysteries of the larger universe.

The vast electronic atlas was compiled from data collected by the Gaia Observatory of the European Space Agency, which has been scanning the sky since its takeoff in 2013 from Kourou in French Guiana.

The map contains enough detail for astronomers to measure the acceleration of the solar system and calculate the mass of the galaxy. These in turn will provide clues as to how the solar system was formed and how quickly the universe has grown since the dawn of time.

Nicholas Walton, a member of the ESA Gaia science team at the Cambridge Astronomical Institute, compared the effort to fill in the blanks on old maps that marked unknown regions with the statement “Here, dragons ”.

“What we’re really doing here is getting a very detailed three-dimensional map of the local universe for stars a few hundred light years away,” he said.

By mapping the positions and movements of stars, the probe discovered destructive processes beyond the edge of the Milky Way. A weak flow of stars spotted between two nearby galaxies is proof that the Large Magellanic Cloud, more massive, regularly devours the Small Magellanic Cloud, smaller.

Many of the bodies Gaia observes are quasars, extremely distant, intensely luminous objects powered by black holes a billion times the mass of the sun. By measuring the movement of the solar system relative to these, Gaia data shows that the solar system falls towards the center of the Milky Way with an acceleration of about 7mm per second every year.

Known as the Galaxy Surveyor, Gaia circles the planet from a gravitationally stable position known as the Lagrange point 930,000 miles from Earth in the direction opposite to the sun. Over the past seven years, the probe has measured the positions and speeds of nearly 2 billion stars. In addition to revealing traces of cosmic consumption, the data allows astronomers to reconstruct the distribution of matter in the Milky Way, from which they will directly estimate its mass.

Lagrange points are regions of space where gravitational forces tend to cause objects to stay in place. For the Gaia Observatory, this means that a minimum of fuel is needed to maintain its location. The distant orbit has another advantage: it is far enough away from Earth to prevent light pollution from spoiling its view of the stars.

Floor van Leeuwen, who handles data processing for Gaia at the Institute of Astronomy, said the data mine allowed astronomers “to forensic analysis of our stellar neighborhood and tackle questions crucial on the origin and future of our galaxy ”.

Caroline Harper, head of space science at the British Space Agency, said: “For thousands of years we have been concerned with noting and detailing stars and their precise locations as they expand our understanding of our cosmos. by humanity.

“Gaia has looked at the sky for seven years, mapping the positions and speeds of stars. Thanks to its telescopes, we have in our possession today the most detailed 3D billionaire atlas ever assembled.