Proxima b, which was discovered back in 2016, is not the only planet circling Proxima Centauri as scientists have discovered a new potential 'super-Earth' called Proxima c. (Image credit: NASA)
A new 'Super-Earth' planet orbiting Proxima Centauri, which is the Sun's nearest neighbouring star, has been discovered by scientists, who published the results in the journal Science Advances. The Proxima c is the second possibly habitable planet, though it is believed to be far beyond the snow line or the boundary where water exists only in frozen form. Back in 2016, Proxima b was discovered by scientists, though that planet is much bigger, and closer to the Proxima Centauri star.
The new Proxima c planet is being seen as a prime candidate for a 'super Earth', though it is believed to be much smaller than Proxima b. The new planet takes 5.2 Earth years to complete one orbit around the Proxima Centauri star and is further away from its sun, so it is likely frozen.
It has a minimum mass is half of that of Neptune, which still puts it in the 'super Earth' category, though it is still among the low mass ones. However, the planet is believed to have a surface temperature of minus 234 degrees Celsius.
In the paper, the scientists have said that the discovery of Proxima c "is highly significant for planet formation models." This is because the planet would have one of the longest periods for orbiting around the star, and a minimum mass in the super-Earth regime, which have been presently detected with using the existing radial velocity (RV) technique.
This RV technique is used by researchers to detect new planets around low-mass or M-type stars. Because the M-type stars have a low mass, the new worlds are tracking by seeing how these stars 'wobble' in response to the gravitational pull from these planets, which are orbiting them. The Proxima Centauri is a small low-mass star, which is located nearly 4.2 light years away from Earth, and is believed to be the closest star to our Sun.
Super Earths are rocky planets that bigger than Earth, without a huge gas envelope surrounding them. According to NASA, these Super Earth's are planets, which are 10 times more massive than Earth with a rocky surface. But scientists do not yet know for certainty is when the planets lose their rocky surface. Nor is it clear if these planets could support life in the future. An earlier NASA research said Proxima b is unlikely to host alien life, though it is believed to be in the habitable zone, where liquid water will stay in its stable form.
Promixa b is also orbiting the Proxima Centauri star. According to NASA, its mass is believed to be 1.27 Earths and it takes 11.2 days to complete one orbit of its star.