Scientists used data from ESA's Gaia space laboratory for studying the Milky way.
Scientists have discovered an ancient galactic core at the centre of the Milky Way, which they are calling as the heart of our galaxy. The cluster of 18,000 stars is from our galaxy's infancy, the researchers said in the study, which has been published The Astrophysical Journal. The researchers used cutting-edge technology, including the most accurate three-dimensional map of the Milky Way ever compiled and neural network that analysed around two million stars. Previous studies had pointed towards this, but it is the first time that scientists have so emphatically announced the discovery of remnants of the past.
The 18,000 stars are from a time when the Milky Way was just a compact collection of proto-galaxies coming together to form a bigger thing.
"But our results significantly flesh out the existing picture by showing that there is indeed a tightly bound in situ 'iceberg,' whose tips have been recognised before," said the team led by astronomer Hans-Walter Rix of the Max Planck Institute for Astronomy.
Mr Rix and his colleagues termed these stars as "poor old heart" of the Milky Way.
The researchers used data collected by the European Space Agency's (ESA's) Gaia laboratory that has been orbiting the Sun for years. Gaia's measurements allowed scientists to estimate the stars' metallicity, which revealed when they were formed.
After the Big Bang 13.8 billion years ago, the primordial universe mainly consisted of hydrogen, with a little bit of helium. When the stars bean to form, their hot dense cores started to smash atoms together to form heavier elements - hydrogen into helium, helium into carbon, and so on.
The later in the universe a star forms, the more metals it is likely to have. Scientists found this group of two million stars that had similar ages and metallicities. They are, the researchers found, more than 12.5 billion years old.