Blue stragglers, a class of stars on open or globular clusters that stand out as they are bigger and bluer than the rest of the stars, have intrigued scientists who have for long probed their origin.
Indian researchers found that half of the blue stragglers samples they studied were formed through mass transfer from a close binary companion star, one third are likely formed through collisions of 2 stars, and the remaining are formed through interactions of more than 2 stars.
A bunch of stars born at the same time from the same cloud form a star cluster. As time passes, each star evolves differently depending on its mass. The most massive and bright stars evolve and move off the main sequence creating a bend in their track, known as the turnoff.
This first-ever comprehensive analysis of blue stragglers is published in the journal Monthly Notices of the Royal Astronomical Society. The researchers compared the mass of the blue stragglers to the mass of the turnoff stars, which are the most massive ‘normal’ stars in the cluster.