The European Space Agency (ESA) has released the most comprehensive map of our Milky Way galaxy. The map, which is based on the latest data from the ESA’s Gaia mission, includes the positions, distances and motions of nearly 1.7 billion stars, as well as asteroids within our Solar System.
“The observations collected by Gaia are redefining the foundations of astronomy,” says Günther Hasinger, ESA Director of Science in a news release. “Gaia is an ambitious mission that relies on a huge human collaboration to make sense of a large volume of highly complex data. It demonstrates the need for long-term projects to guarantee progress in space science and technology and to implement even more daring scientific missions of the coming decades.”
The Gaia spacecraft was launched in December 2013, and it began scientific operations the following year. In September 2016, the first data release, based on just 14 months of observations, was published. The dataset contained distances and motions of two million stars.
The newly released data, which is based on 22 months of charting the sky, is far more extensive and meticulous. It contains the location of nearly 1.7 billion stars with a much higher precision. It also registers the parallax motion of the stars – the apparent displacement of the stars caused by Earth’s yearly orbit around the Sun, and velocity of more than 1.3 billion stars.
“The second Gaia data release represents a huge leap forward with respect to ESA’s Hipparcos satellite, Gaia’s predecessor and the first space mission for astrometry, which surveyed some 118,000 stars almost thirty years ago,” says Anthony Brown of Leiden University, The Netherlands. “The sheer number of stars alone, with their positions and motions, would make Gaia’s new catalogue already quite astonishing.”
The comprehensive dataset also provides information such as brightness data of all surveyed stars, colour measurements of just about all of them and how the brightness and colour of half a million stars change over time. The surface temperatures, including the effects of the interstellar dust on about hundred million of them have also been measured. Gaia has also identified the positions of more than 14,000 known asteroids hurling in our Solar System.
Also using what the Gaia spacecraft has catalogued so far, scientists were able to see the motions of 75 globular clusters, and 12 dwarf galaxies that revolve around our galaxy. Information needed to study the past evolution of our Galaxy and its environment; the gravitational forces and the distribution of the elusive dark matter have also been included in the newly released Gaia’s dataset.
“Gaia is astronomy at its finest,” says Fred Jansen, Gaia mission manager at ESA. “Scientists will be busy with this data for many years, and we are ready to be surprised by the avalanche of discoveries that will unlock the secrets of our Galaxy.”
The findings have been published in the journal Astronomy & Astrophysics. You can watch the Gaia’s team describing their findings in the video below.
Source: The European Space Agency (ESA)