A few stars in the Milky Way Galaxy have undergone a change in their colour due to a supermassive black hole right in the centre of the galaxy, reveals a recent research. Our galaxy is home to many stars and some of those include red giants which are luminous ones that are larger and cooler than expected.
In a paper published online in the Astrophysical Journal, astrophysicists have come up with a theory saying that the supermassive black hole, Sagittarius A* launched a powerful jet of gas that took away the red giants’ outer layers. There are millions of stars, 1.6 light-years of Sagittarius A*. However, scientists observed that it has fewer red giant stars than expected. The study suggests that the mighty jet released from the black hole is the cause of transformation of the stars into smaller red parts that are hotter and bluer.
The research paper published on November 12 is written by Michal Zajaček, an astrophysicist at the Polish Academy of Sciences in Warsaw, Anabella Araudo from the Institute of Physics of the Czech Academy of Sciences, Vladimír Karas from Astronomical Institute of the Czech Academy of Sciences, Bożena Czerny from Warsaw’s Center for Theoretical Physics, and Andreas Eckart from University of Cologne.
Science News reports that according to astrophysicists, the supermassive black hole Sagittarius A* is calm but it is the two giant bubbles of gamma-ray-emitting gas rooted at the center of the Milky Way, one at the top and one below the galaxy’s plane. These structures are known as the Fermi bubbles. Researchers believe that the presence of these gamma-ray-emitting bubbles means that the black hole came into existence around 4 million years ago when something fell into it.
The study suggests that it was around that time that the black hole released a powerful jet of material into its stellar surrounding that affected the red giants in the vicinity of Sagittarius A*. According to Science News, Zajaček says that the jet release acted on large red giants since they can be effectively evaporated by it. It is due to this vigorous jet release that scientists cannot spot the biggest and brightest red giants near the galactic centre of the Milky Way.
Scientists believe that the creation of Fermi bubbles could have been the result of a period when many stars formed and exploded in our galaxy’s heart. Further study of the X-ray and gamma-ray rich Fermi bubbles could help reveal the cause and history of the Milky Way Galaxy.