Astronomers Discover First Solar Sibling: Sister Sun is 110 Light-Years from Earth
Astronomers have now found our sun's first sibling--a star that was probably born from the same cloud of gas and dust as the sun. Now, scientists have learned a bit more about this star located 110 light-years away, revealing more about our own closest star.
"We want to know where we were born," said Ivan Ramirez, one of the researchers, in a news release. "If we can figure out in what part of the galaxy the sun formed, we can constrain conditions on the early solar system. That could help us understand why we are here."
The new star is called HD 162826 and is about 15 percent more massive than the sun. Located in the constellation Hercules, it's invisible to the naked eye. However, it can easily be seen with low-powered binoculars not far from the bright star Vega.
So how did scientists come to the conclusion that this was the sun's sibling? The researchers examined 30 possible candidates that could potentially be solar siblings. The scientists studied 23 of these stars in depth using high-resolution spectroscopy. They conducted chemical analysis and looked at the stars' orbits, where they began and where they were going in their paths around the center of the Milky Way galaxy. They eventually narrowed the 23 stars down to one: HD 162826.
"The idea is that the sun was born in a cluster with a thousand or a hundred thousand stars," said Ramirez in a news release. "This cluster, which formed more than 4.5 billion years ago, has since broken up. A lot of things can happen in that amount of time."
The findings reveal a little bit more about our sun and possible solar relatives. Once more solar siblings are identified, scientists will be closer to understanding where and how the sun formed. Currently, astronomers are working on models to run the orbits of all known solar siblings backward in time to find out where they intersect.
The findings are published in the Astrophysical Journal.