http://www.utexas.edu/news/2014/05/08/sun-sibling-astronomy/

AUSTIN, Texas — A team of researchers led by astronomer Ivan Ramirez of The University of Texas at Austin has identified the first “sibling” of the sun — a star almost certainly born from the same cloud of gas and dust as our star. Ramirez’s methods will help astronomers find other solar siblings, which could lead to an understanding of how and where our sun formed, and how our solar system became hospitable for life. The work appears in the June 1 issue of The Astrophysical Journal.

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The solar sibling his team identified is called HD 162826, a star 15 percent more massive than the sun, located 110 light-years away in the constellation Hercules. The star is not visible to the unaided eye but easily can be seen with low-power binoculars, not far from the bright star Vega.

The team identified HD 162826 as our sun’s sibling by following up on 30 possible candidates found by several groups around the world looking for solar siblings. Ramirez’s team studied 23 of these stars in depth with the Harlan J. Smith Telescope at McDonald Observatory, and the remaining stars (visible only from the southern hemisphere) with the Clay Magellan Telescope at Las Campanas Observatory in Chile. All of these observations used high-resolution spectroscopy to get a deep understanding of the stars’ chemical make-up.

But several factors are needed to really pin down a solar sibling, Ramirez said. In addition to chemical analysis, his team also included information about the stars’ orbits — where they had been and where they are going in their paths around the center of the Milky Way galaxy. Considering both chemistry and orbits narrowed the field of candidates down to one: HD 162826.

Soso said:

http://www.utexas.edu/news/2014/05/08/sun-sibling-astronomy/

AUSTIN, Texas — A team of researchers led by astronomer Ivan Ramirez of The University of Texas at Austin has identified the first “sibling” of the sun — a star almost certainly born from the same cloud of gas and dust as our star. Ramirez’s methods will help astronomers find other solar siblings, which could lead to an understanding of how and where our sun formed, and how our solar system became hospitable for life. The work appears in the June 1 issue of The Astrophysical Journal.

…

The solar sibling his team identified is called HD 162826, a star 15 percent more massive than the sun, located 110 light-years away in the constellation Hercules. The star is not visible to the unaided eye but easily can be seen with low-power binoculars, not far from the bright star Vega.

The team identified HD 162826 as our sun’s sibling by following up on 30 possible candidates found by several groups around the world looking for solar siblings. Ramirez’s team studied 23 of these stars in depth with the Harlan J. Smith Telescope at McDonald Observatory, and the remaining stars (visible only from the southern hemisphere) with the Clay Magellan Telescope at Las Campanas Observatory in Chile. All of these observations used high-resolution spectroscopy to get a deep understanding of the stars’ chemical make-up.

But several factors are needed to really pin down a solar sibling, Ramirez said. In addition to chemical analysis, his team also included information about the stars’ orbits — where they had been and where they are going in their paths around the center of the Milky Way galaxy. Considering both chemistry and orbits narrowed the field of candidates down to one: HD 162826.

Brilliant. I had thought is was impossible. The Sun has orbited the Milky Way about 18.4 times since its birth as well as wandering up and down through the plane of the Milky Way about 2.7 times per orbit, and that’s plenty of time for any stars initially born near the Sun to have wandered off (due to orbit ellipticity and local gravity variations) so far as to make finding it impossible.

Thanks moll, you answered my question. Although, I still don’t understand how one can be so sure the stars were born from the same cloud (it’s probably waaaaay above the limit of my smarts :) )