While scanning the universe through the Hubble Space Telescope, an international team of astronomers has found a fossilised remnant of the early Milky Way located 19,000 light years away from Earth and it contains unusual mix of stars with very high age differences.
This stellar system named Terzan 5 has been classified as a globular cluster since it was first discovered 40 years ago. This globular cluster is unique and resembles no other clusters previously known. According to scientists, the Terzan 5 is around 12 billion years old and looks pretty good and matured for its age.
What’s striking about the galaxy is that it has stars that are amazingly similar to the ancient stars of our galaxy Milky Way. Astronomers believe that studying this galaxy will help in understanding the past and present of our galaxy.
Researchers used the Advanced Camera for Surveys and the Wide Field Camera 3 on board The Hubble Space Telescope to monitor the Terzan 5 and found two different stars that differ by 7 billion years in age. Such a huge difference in the age of stars reveal that star production happened in two bursts in the galaxy and it wasn’t continuous as previously thought by astronomers.
“This requires the Terzan 5 ancestor to have large amounts of gas for a second generation of stars and to be quite massive. At least 100 million times the mass of the Sun,” said Davide Massari, co-author of the study, from INAF in Italy, and the University of Groningen in the Netherlands.
Milky Way galaxy formed when vast clumps of gas and stars interacted with each other to form the primordial bulge. According to study authors, these gaseous clumps could remain relatively undisrupted for very long and keep existing embedded within the galaxy. Such galaxies help astronomers in revealing key information about the past of our Milky Way.
Terzan 5 has stellar population which is strikingly similar to the galactic bulge located in the central region of our galaxy. Scientists say that Terzan 5 has survived billions of years and it is a remnant of the distant past of the Milky Way.
Hubble Space Telescope (HST) was launched back in 1990 and since then it has peeked into the deepest corners of the universe. HST is a joint venture of NASA and ESA while it is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland. At present, it is the largest telescope present in the orbit. However, soon it will be replaced by the NASA’s James Webb Telescope which has thrice larger lens than HST.