A new study released by researchers at UC Berkley and Smithsonian Astrophysical Observatory have concluded that our sun, as well as similar stars, had twins.
Many stars have companions and astronomers have several theories as to how this occurs. Some speculate that stars are simply born with companions whereas others have theorized that one star was captured by the gravity of another star. Another question that interests astronomers is rather or not binary star systems occasionally split resulting in a single-star system.
While this does have implications regarding our own solar system, this discovery also yields insight into the formation of galaxies.
Scientists have used computer models to simulate how, under the effects of gravity, gasses can be condensed into stars. One such simulation, led Pavel Kroupa of the University of Bonn, concludes that all stars are born with companions. The direct evidence for this theory, however, was lacking until the Perseus study was released.
The Sun's Evil Twin
The hypothetical companion to our sun has been dubbed Nemesis because it is thought to have been responsible for the asteroid which wiped out the dinosaurs. Despite their search, astronomers have found no evidence for the existence of Nemesis; however, the Perseus study has led researchers to believe that Nemesis did exist.
"We are saying, yes, there probably was a Nemesis, a long time ago," said study co-author Steven Stahler.
As for the fate of Nemesis, it is theorized that it eventually drifted farther into the Milky Way galaxy and hasn't been seen since then.
The research is based on a recently conducted radio survey of a molecular cloud that was fill of recently born stars in the Perseus constellation. According to the researchers, the math used in the Perseus study only adds up if stars are born as "wide binaries."
While the concept of twin stars might make one think of the classic Star Wars image of Luke looking out over twin sunsets, it might not look so impressive in real life. In the context of the recently released study, "wide" means that the twin stars are separated by at least 500 million astronomical unit. An astronomical unit is measured as the distance between the Earth and the Sun which is 93 million miles. This means that Nemesis would have been 17 times farther away from the sun than Neptune is.