Close Call: Astronomers Pinpoint the Nearest Known Flyby of a Star

Dim star likely passed through solar system's Oort Cloud.

ByABC News
February 18, 2015, 12:33 PM
An artist's conception shows Scholz's star and its brown dwarf companion, foreground, during their flyby of our solar system that astronomers believe occurred 70,000 years ago.
An artist's conception shows Scholz's star and its brown dwarf companion, foreground, during their flyby of our solar system that astronomers believe occurred 70,000 years ago.
Michael Osadciw/University of Rochester

— -- Astronomers have pinpointed the closest flyby ever of a dim star, which is believed to have passed through the solar system's cloud of comets around 70,000 years ago.

Considering the vast abyss of space, this was a close encounter. At its nearest point, the newly discovered Scholz's star was believed to have been 0.8 light years from the solar system -- that's about 5 trillion miles.

The only other star that has ever gotten closer to Earth is the sun. Scholz's star and the sun are now 20 light years apart, according to astronomers at the University of Rochester. The findings were published in Astrophysical Journal Letters and were a collaboration from a team spanning the globe.

Eric Mamajek from the University of Rochester and the group closely studied the velocity and the path of the dim star.

"The small tangential motion and proximity initially indicated that the star was most likely either moving towards a future close encounter with the solar system, or it had 'recently' come close to the solar system and was moving away," he said in a statement.

"Sure enough, the radial velocity measurements were consistent with it running away from the Sun's vicinity -- and we realized it must have had a close flyby in the past."