A recent model on how stars are formed adds weight to the idea that most stars are born in a litter with at least one sibling.
Our own star at the center of the Solar System is probably no exception, and some scientists theorize that the Sun's estranged twin might be to blame for the death of the dinosaurs.
Two researchers from UC Berkeley and the Harvard-Smithsonian Astrophysical Observatory used data from a radio survey to conclude that all Sun-like stars are probably born with a companion.
The only model that could reproduce the data was one in which all stars form initially as wide binaries.
Astronomers have wondered if the large number of stars in our galaxy are created close to one another or if they fall in together after they've formed.
The 'born together' hypothesis has been the favorite, and simulations have shown that almost all stars could be born as multiples.
This new work is exciting because of the limited evidence supporting these simulations.
"Our work is a step forward in understanding how binaries form and how they play a role in early stellar evolution," said Stahler.
The researchers mapped the radio waves leaking out of a dense cocoon of dust about 600 light-years away that contained a whole nursery of young stars.
The survey allowed for a census of stars younger than half a million years old called Class 0 stars, and stars older than 500,000 years old called Class 1.
The scientists found 45 lonely stars, 19 binary star systems, and a further five that contained more than two stars, with the help of data on the shapes of the surrounding cloud of dust.
They changed their conclusion to say that most stars formed inside the dense cores of dust clouds are born with a partner.
"I think we have the strongest evidence to date for such an assertion," said Stahler at the time.
The researchers found that all of the binaries that were separated by 500AU or more were Class 0 and lined up with the axis of the cloud surrounding them.
Class 1 stars were closer together at around 200AU and weren't aligned with the 'egg's' axis.
Sarah Sadavoy from the Harvard-Smithsonian Astrophysical Observatory said that it isn't random and must say something about the way wide binaries form.
Where is ours if most stars are born with a partner?
A distance of 500AU is under 3 light-days. The nearest star to be seen is Proxima Centauri, which is almost 300,000AU away, and the closest probe is just under 140AU away.
If the Sun has a twin, it's hard to see in our neighborhood.
There is a theory that our Sun has a twin that likes to stir things up.
This theoretical trouble maker has been proposed as a reason for the extinction of most of the dinosaurs.
A red dwarf star 1.5 light-years away could occasionally travel through the icy outer limits of our Solar System, stirring up material with its gravity, and knocking a few more space boulders our way, according to an astronomer from the University of California Berkeley named Richard Muller.
A brown dwarf, a dim star, could explain the odd, wide, and sometimes dwarf planet, Sedna.
There's no sign of a long-lost partner for our Sun.
"We are saying that there probably was a Nemesis a long time ago," said Stahler.
Our Sun would have gathered the lion's share of dust and gas, leaving its twin dark and stunted.
It's a little pissed off.
The research was published in a journal.
The first version of this article was published in June.
