London: Turning previous theories on their head, an Indian-origin researcher has claimed that there are many solitary sun-like stars in the universe, which exist without any stellar companion.
The finding by Deepak Raghavan of Georgia State University in Atlanta and colleagues boosts the likelihood that there are other life-friendly solar systems in the universe.
Previous surveys had suggested that most systems containing a star the same mass as our sun have two or more stars orbiting each other, in contrast to our solar system.
However, Raghavan has thrown this hypothesis in doubt—his team looked at 454 sun-like stars, and found that 56 per cent were single like our sun and just 44 per cent had a stellar companion.
The finding is at odds with a survey completed in 1991, which found that the majority of systems containing a sun-like star were multiple star systems, reports New Scientist.
One reason for the conflicting results could be that the 1991 survey was based on a smaller sample.
Also, its authors assumed that some stars in the sample had companions that were below the survey’s detection threshold.
This may have led them to overestimate the number of companion systems, suggests Raghavan`s team.
Single stars provide a stable planetary system, which makes them suitable for life.
Planets can form in multiple star systems, but the gravity of the additional stars can hurl planets into their parent star, said John Chambers of the Carnegie Institution for Science based in Washington DC, who was not involved in the study.
The study will be published in The Astrophysical Journal.