Thursday, July 21, 2016

A System of Two Warm Super-Earths


Affer et al. (2016) present the discovery of a planetary system consisting of two super-Earths in orbit around a red dwarf star with approximately half the mass and half the size of the Sun. Additionally, the red dwarf star has ~4 percent the Sun's luminosity and its effective temperature is 3722 ± 68 K. The two super-Earths are identified as GJ3998b and GJ3998c. Both planets were discovered via the radial velocity method. The inner planet, GJ3998b, has at least 2.47 ± 0.27 times the mass of Earth and its orbital period is 2.65 days. The outer planet, GJ3998c, has at least ~6.26 times the mass of Earth and its orbital period is 13.74 days. Estimates indicate that the equilibrium temperatures of GJ3998b and GJ3998c are ~740 K and ~420 K, respectively.

Reference:
Affer et al. (2016), "The HADES RV Programme with HARPS-N@TNG - GJ 3998: An early M-dwarf hosting a system of Super-Earths", arXiv:1607.03632 [astro-ph.EP]