Blue straggler – bigger and bluer star formed when one star eats up another

What is the News?

Indian researchers have done a comprehensive analysis to understand the formation of blue stragglers.

What are Blue Stragglers?

Blue stragglers are a class of stars on open or globular clusters. They stand out as they are bigger and bluer than the rest of the stars.

Note: A globular cluster is a spherical collection of stars. Globular clusters are very tightly bound by gravity giving them their spherical shapes and high concentrations of stars toward their centers.

First Discovered by: Blue stragglers were first discovered by Allan Sandage in 1953.

About the study by Indian Researchers:

Indian Researchers have studied 228 clusters with a total of 868 blue stragglers. They compared the mass of the blue stragglers to the mass of the turnoff stars (which are the most massive ‘normal’ stars in the cluster) and predicted the formation mechanisms. They have found that:

1. Half of the blue stragglers are formed through mass transfer from a close binary companion star,
2. One third are likely formed through collisions of 2 stars and
3. The remaining are formed through interactions of more than 2 stars.

Significance of this study:

The study will help improve understanding of the stellar systems. It will help uncover exciting results in studies of large stellar populations including galaxies.

Source: This post is based on the article “Blue straggler – bigger and bluer star formed when one star eats up another” published in PIB on 2nd September 2021.