Astronomers find large cold planet orbiting one of nearest stars

An international team of astronomers has detected evidence of a cold planet at least three times the size of Earth orbiting an ancient red dwarf star, right in our stellar neighbourhood.

If you were travelling at the speed of light, it would take you just six years to reach it.

In the context of the universe, that’s basically right next door.

The newly discovered world, described Wednesday in Nature, is associated with a small, dim star known as Barnard’s star that is older than our solar system. It takes the planet 233 days to complete a single orbit around its cool red sun.

It is now the secondclosest known planet to our solar system.

The only closer known planet is an Earth-sized body that orbits the small red star Proxima Centauri in the Alpha Centauri triple star system. That planet was discovered in 2016 and lies just four light-years from Earth.

The planet around Barnard’s star is probably too cold to host life, researchers said.

Although it is about as close to its own star as Mercury is to the sun, scientists say it is probably as cold as Saturn. That’s because Barnard’s Star emits only 0.4 per cent of the sun’s radiant power. But the new discovery is exciting for other reasons.

The proximity of the newly found planet to Earth makes it an excellent target for future observations. It is so close that the next generation of telescopes may be able to image it directly, the researchers said.

In addition, the new find provides further evidence that planets are nearly ubiquitous around red dwarf stars, said Ignasi Ribas, an astronomer and director of the Institute of Space Studies of Catalonia in Spain, who led the work.

‘‘The chances of finding new ones is quite high,’’ he said.

The new detection was made by a team of scientists working on an astronomy collaboration called Red Dots. Together, they are scanning the night sky for planets orbiting nearby dim red dwarf stars. Ultimately they hope to find a world in the habitable zone of these stars, where liquid water could pool on its surface.

– LA Times