Scientists claim to have discovered 'ancient heart' of galaxy
Research: The stars formed 12.5 billion years ago in Constellation Sagittarius. Protogalaxy covers more than 18,000 light-years
Muskan 
Washington. Astronomers claim to have discovered the 'ancient heart' of our galaxy. All the stars and planets developed around this ancient nucleus. The oldest stars in the Milky Way are in Constellation Sagittarius. These stars were formed 12.5 billion years ago.
Astronomer Hans Walter Rix of the Max Planck Astronomy Institute in Germany says that it has long been speculated that large populations of older stars must be present at the center of our galaxy. The data now shows that they are there. Rix's colleagues reported that the ancient heart of the Milky Way is a spherical protogalaxy, covering more than 18,000 light-years. A protogalaxy is a place from which the evolution of the Milky Way is believed. The study helps to strengthen our understanding of the early phase of the Milky Way, said astronomer Vasily Belokurov from the University of Cambridge.
Researchers at the Sagittarius Constellation looked at nearly two million stars with a metal-to-hydrogen ratio. After examining the motion of stars, astronomers focused only on those stars that do not move in the halo of low-metal stars around the disk of the galaxy. In the end result, astronomers sampled 18,000 older stars, which represent the Milky Way's first nucleus.
Astronomers believe that little was understood about the beginning of the Milky Way. The new study provides a greater understanding of the overall structure. Glimpses of these stars had been seen earlier also. Ricks and his team conducted the study using data from the Gaia satellite. This satellite was launched in 2013 with the goal of mapping the Milky Way Galaxy.
