New evidence supports hypothesis that stars are born in a litter
15 Jun 2017
A new model on how stars were formed lends support to the hypothesis that most, if not all stars were born in a litter with at least one sibling.
After analysing data from a radio survey conducted on a dust cloud in the Perseus constellation, two researchers from UC Berkeley and the Harvard-Smithsonian Astrophysical Observatory concluded all Sun-like stars were probably born with a companion.
"We ran a series of statistical models to see if we could account for the relative populations of young single stars and binaries of all separations in the Perseus molecular cloud, and the only model that could reproduce the data was one in which all stars form initially as wide binaries," said University of California at Berkeley astronomer Steven Stahler.
Astronomers had for years, wondered whether the large number of binary and triple systems of stars in our galaxy had been created close to one another, or if they fell in together after they had formed.
Astronomers had also searched for a companion to our sun, a star dubbed Nemesis as it was supposed to have kicked an asteroid into the earth's orbit that collided with our planet and exterminated the dinosaurs. Also it had never been found.
The new support was based on a radio survey of a giant molecular cloud filled with recently formed stars in the constellation Perseus, as also mathematical model that could explain the Perseus observations only if all sunlike stars were born with a companion.
"We are saying, yes, there probably was a Nemesis, a long time ago," said co-author Steven Stahler, a UC Berkeley research astronomer.
In the study, "wide" meant that two stars were separated by more than 500 astronomical units, or AU, where one astronomical unit was the average distance between the sun and earth (93 million miles).