Blue Stragglers

Recently, scientists from the Indian Institute of Astrophysics, Bengaluru, conducted a study on blue stragglers, a particular type of star seen in clusters and also, sometimes, alone. The researchers have found support for one way to understand the aberrant behaviour of blue stragglers.

• For the study, the researchers used the UVIT instrument (Ultra Violet Imaging Telescope) of ASTROSAT, India’s first science observatory in space.

Blue Stragglers: Blue Straggler Stars are hot, blue, massive stars and seem to have a different trajectory of evolution from the norm.

• There are a few stars that, when they are expected to start expanding in size and cooling down, do just the opposite.
• They grow brighter and hotter as indicated by their blue colour, thus standing out from the cooler red stars in their vicinity in the color-magnitude diagram.
• Since they lag their peers in evolution, they are called stragglers, more specifically, blue stragglers, because of their hot, blue colour.
• Most are located at least several thousand light-years away from the Sun, and most are around 12 billion years old or more.