Indian scientists have discovered 57 variable stars in the open cluster NGC 381, Science X Network reported.
An open star cluster is also a group of stars consisting of a single giant molecular cloud. The luminaires in such a cluster are weakly interconnected and can be destroyed during movement through the galaxy. In total, astronomers know more than 1000 such formations, and the study of their distribution in the galaxy is crucial for understanding the evolution of the universe.
Located about 3,700 light-years from Earth in the constellation Cassiopeia, NGC 381 is a middle-aged (about 447 million years) open cluster with a radius of about 15 light-years and a mass of about 32.4 solar masses. Indian astronomers studied it with the 1.3-metre Devasthal optical telescope. “We are actively observing the open cluster region NGC 381 in the V and I bands to study shifting stars. The data were collected over a period of 27 nights, from October 1, 2017 to January 14, 2019, over a year,” the scientists said.
As a result, the team identified a total of 57 variable stars, 5 of which belong to the cluster itself, in the NGC 381 region. The astronomers classified these stars according to their light curves, amplitude of brightness changes, and their position on Hertzsprung-Russell. Diagram (relating the spectral type and mass of stars).
According to the study, 10 of the 57 variables identified are shaded binaries, meaning the brightness changes as one star shadows another. 15 were variable stars of the rotating type and two were of the pulsating type.
The remaining 30 stars cannot be attributed to any genre.