A group of astronomers led by Laetitia Delrez of the University of Liege in Belgium have discovered two new super-Earth class planets, designated LP 890-9 b and LP 890-9 c, that are slightly larger than Earth. The finding has been published in Astronomy & Astrophysics.
“Super-Earths” are planets more massive than Earth but not exceeding the mass of Neptune. To find them they used NASA’s Transiting Exoplanet Survey Satellite (TESS).
“We have presented the discovery and initial characterization of the LP 890-9 system, which hosts two temperate super-Earths transiting a nearby M6 dwarf,” the researchers wrote in the paper.
LP 890-9 b has a radius of about 1.32 Earth radii and its mass is estimated to be no more than 13.2 Earth masses. The planet orbits its host every 2.73 days at a distance of about 0.018 AU from it. The equilibrium temperature of LP 890-9 b was calculated to be 396 K.
Meanwhile, in the case of LP 890-9 c, its radius was measured to be almost 1.37 Earth radii, while its mass is assumed to be less than 25.3 Earth masses. The exoplanet is separated from its parent star by 0.04 AU and has an orbital period of about 8.46 days. The equilibrium temperature of the planet is estimated at a level of 272 K.
“The discovery of the remarkable LP 890-9 system presented in this paper offers another rare opportunity to study temperate terrestrial planets around our smaller, cooler neighbors,” the paper’s authors concluded.