Explained: What is Proxima Centauri? Proxima Centauri is 4.2 light-years away from the Sun – considered a close distance in cosmic terms. Its mass is about an eighth of the Sun’s, and it is too dim to be seen with the naked eye from Earth. Updated: January 6, 2021 8:32:05 am Proxima b, one of the two planets that revolve around the star, is the subject of significant curiosity. (File Photo) Astronomers running the world’s largest initiative to look for alien life have recently picked up an “intriguing” radio wave emission from the direction of Proxima Centauri, the closest star to our Sun, The Guardian reported.