Astronomers Identify the Closest Known Flyby of a Rogue Star to Our Solar System (+Video)

A close call of 0.8 light years

Astronomers identify the closest known flyby of a star to our solar system: a dim star that passed through the Oort Cloud 70,000 years ago

A group of astronomers from the US, Europe, Chile and South Africa have determined that 70,000 years ago a recently discovered dim star is likely to have passed through the solar system’s distant cloud of comets, the Oort Cloud. No other star is known to have ever approached our solar system this close – five times closer than the current closest star, Proxima Centauri.

In a paper published in Astrophysical Journal Letters, lead author Eric Mamajek from the University of Rochester and his collaborators analyzed the velocity and trajectory of a low-mass star system nicknamed “Scholz’s star.”

The star’s trajectory suggests that 70,000 years ago it passed roughly 52,000 astronomical units away (or about 0.8 light years, which equals 8 trillion kilometers, or 5 trillion miles). This is astronomically close; our closest neighbor star Proxima Centauri is 4.2 light years distant. In fact, the astronomers explain in the paper that they are 98% certain that it went through what is known as the “outer Oort Cloud” – a region at the edge of the solar system filled with trillions of comets a mile or more across that are thought to give rise to long-period comets orbiting the Sun after their orbits are perturbed.

University of Rochester

Read more here: A close call of 0.8 light years
 http://www.rochester.edu/newscenter/scholz-star/

The Astrophysical Journal Letters
The Closest Known Flyby of a Star to the Solar System
http://iopscience.iop.org/2041-8205/800/1/L17/pdf/2041-8205_800_1_L17.pdf

Image Credit: Artist’s conception of Scholz’s star and its brown dwarf companion (foreground) during its flyby of the solar system 70,000 years ago. The Sun (left, background) would have appeared as a brilliant star. The pair is now about 20 light years away. Credit: Michael Osadciw/University of Rochester.