Hubble Spotted Terzan 5, The Remnant Of The Early Milky Way
Terzan 5, which is considered the "old ones" of the Milky Way, is revealed by an international team of astronomers. It is a globular star cluster about 19,000 light years from Earth, which composed mainly of an ancient big ball of stars resembling spilled sugar like other globular clusters.
Science Daily reports that the team of astronomers searched data from the Advanced Camera for Surveys and the Wide Field Camera 3 on board the Hubble. They discovered that there are two apparent kinds of stars in Terzan 5. These not only differ in the elements they have but also have an age gap of around 7 billion years.
Davide Massari, the co-author of the study explained that this requires the Terzan 5 ancestor to have large amounts of gas for the second generation of stars and to be quite massive, which is at least 100 million times the mass of the Sun. The Universe Today reports that Terzan 5 is a paradigm for the title of "living fossil" from the ancient days of Milky Way. Theories of galaxy formation indicate that huge clumps of gas and stars intermingled to shape the primordial bulge of the Milky Way.
Meanwhile, Francesco Ferraro from the University of Bologna, Italy and the lead author of the study thought that some remnants of these gaseous clumps remain relatively undisrupted and keep existing embedded within the galaxy. He further said that such galactic fossils permit astronomers to reconstruct a significant piece of the history of the Milky Way.
The discovery of Terzan 5 could provide a perception of the galaxy assembly. It could also help astronomers to resolve the mysteries of the galaxy formation and perceive the complicated history of the Milky Way. Ferrero also explained that Terzan 5 could represent an intriguing link between the local and the distant Universe, a surviving witness of the Galactic bulge assembly process.