Gaia space probe maps more than a billion stars in Milky Way, matches the count of India’s population

So how many stars do you think are there in the milky way? A few lakhs, a few millions? You may run out of count but the European space agency has the answer for you. And the count is more than a billion stars, 1.15 billion to be precise. This figure matches the count of total population of India.

The Gaia space probe, which was launched in 2013, has mapped the stars that are vastly expanding the inventory of known stars in our galaxy, the European Space Agency said. Gaia adopts a couple of ways to map the position of the stars in the Milky Way.

The probe not only pinpoints their location by scanning each star multiple times but also plots their movement. The data released on Wednesday includes both kinds of data for some two million stars.

That catalogue is set to expand 500-fold over the course of Gaia’s five-year mission. Orbiting the Sun 1.5 million kilometres beyond Earth’s orbit, the European probe started collecting data in July 2014.

Released to eagerly waiting astronomers around the world, the initial catalogue of 1.15 billion stars is “both the largest and the most accurate full-sky map ever produced,” said French astronomer Francois Mignard, a member of the 450-strong Gaia consortium.

In a web-cast press conference at the ESA Astronomy Centre in Madrid, scientists unveiled a stunning map of the Milky Way, including stars up to half a million times feinter than those that can be seen with the naked eye.

The images were captured by Gaia’s twin telescopes - scanning the heavens over and over - and a billion-pixel camera, the largest ever put into space.

The resolution is sharp enough to gauge the diameter of a human hair at a distance of 1,000 kilometres, said Anthony Brown, head of the Gaia data processing and analysis team.

(With inputs from PTI)