New research has proved the presence of 15 exoplanets orbiting smaller, cooler red dwarf stars. These include three purported “super-Earths,” one of which is believed to have water liquid – a key ingredient for life.
Researchers elaborated their observations on data from the Kepler space telescope’s K2 mission, which were joined with findings made using ground-based telescopes, such as Spain’s Nordic Optical Telescope and Hawaii’s Subaru Telescope. This conceded them to confirm the 15 new exoplanets and their host stars, including K2-155, which is located around 200 light-years from Earth.
Three super-Earths were found to be orbiting that bright red dwarf, but it was the outermost planet, K2-155d, that stood out as possibly being within K2-155’s habitable zone.
Hirano said, “Red dwarf systems, especially coolest red dwarfs, are just beginning to be investigated, so they are very exciting targets for future exoplanet research.”
Hirano further commented on the finding that planets that orbit red dwarfs have a similar radius gap to planets orbiting solar-type stars, saying that his team’s discovery was “unique,” and that astronomers are presently trying to investigate the reason behind the radius gap.
Furthermore, he speculated that photoevaporation, a phenomenon where electromagnetic radiation strips away a planet’s atmosphere, might be the reason why there aren’t too many large planets close to their host stars and that the metallic content of a host star could be related to the size of the planets that orbit it.
“Large planets are only discovered around metal-rich stars. What we found was consistent with our predictions. The few planets with a radius about three times that of Earth were found orbiting the most metal-rich red dwarfs.”
TESS will examine more than 200,000 stars for their transits, or instances when a planet passes right in front of its host, according to NASA. The space agency also hopes to document over 1,500 transiting exoplanet candidates with TESS, including about 500 which could be classified as Earth-sized or super-Earth planets.