In the system of YZ Ceti 12 light-years away scientists have just discovered three earth-mass planets orbiting a small red star. The discovery was made on August 14th at the European Souther Observatory.
According to NASA: YZ Ceti is the nearest multi-planet system found orbiting a red dwarf star or “M dwarf.” While the three planets are outside their star’s habitable zone, they are all about the same mass as Earth. YZ Ceti b, c, and d are the lowest mass planets found with the planet-hunting method radial velocity. NASA’s TESS and James Webb telescopes will study more exoplanets around nearby stars in 2018, in hopes of finding another Earth.
You can find the paper that discusses the findings on ArXiv.
The ESO made the discovery using the High Accuracy Radial velocity Planet Searcher (HARPS) a ‘3.6m telescope is dedicated to the discovery of extrasolar planets.’ Using the process known as the radial velocity method a team of researchers was able to determine the size of the exoplanets in relation to the earth’s mass; 0.75, 0.98, and 1.14.
Why This Discovery Is Important
None of these exoplanets appear to be habitable, so it’s understandable to question the merits of this find. However solely due to it’s proximity, this becomes a significant point of research. “The system is at only 3.6 parcsecs [12 light-years], making it very attractive for further characterization,”
It’s distance allows us to better study the properties of red dwarf stars and their surrounding exoplanets. It allows us to better understand the habits of planet formation around red dwarves, specifically with regard to earth-mass objects.
‘M dwarfs are about 70% of the stellar population of the Galaxy and constitute the lower tail of the main sequence in the Hertzsprung–Russell diagram’ it’s important we understand how 70% of the stellar population behaves.