Barnard's star tricked scientists before: why this planet is real.

Scientists say they've finally found a world orbiting Barnard's star, the closest single star to the sun. This rocky planet, discovered with the European Southern Observatory's Very Large Telescope in Chile, is smaller than Earth, and flies around its tiny cool star every three days. Barnard's star is six light-years away from us, in the constellation Ophiuchus. The only closer stars are the trio that make up the Alpha Centauri system. Anyone have déjà vu? Yes, exoplanet hunters have thought before they'd found worlds around this particular star — a popular sci-fi setting — and their discoverers seemed pretty darn sure of their data, too. But this one is the real deal, a new research team says. Honest. "The discovery of this planet, along with other previous discoveries such as Proxima b and d, shows that our cosmic backyard is full of low-mass planets," said Alejandro Suárez Mascareño, a coauthor of the paper published in the journal Astronomy & Astrophysics today. SEE ALSO: Scientists haven't found a rocky exoplanet with air. But now they have a plan. A confirmed exoplanet orbits Barnard's star every three days. Credit: ESO / M. Kornmesser illustration Despite its close proximity to our solar system, Barnard's star is too faint to see with the naked eye. A simple eight-inch amateur telescope should be able to spot it in deep space, though. This special star, a target of exoplanet searches for over a century, has a long history of false positive planet detections. Six years ago, an international team of researchers thought they had found a planet three times larger than Earth, just outside the so-called habitable zone, in the Barnard's star system. The authors of that paper, published in the journal Nature, characterized the world as frozen and circling its red dwarf host star every 233 days. That potential discovery, using the radial velocity method, relied on 771 observations over two decades. Though at the time it was considered an unconfirmed candidate, the lea