The impact of faculae on the radius determination of exoplanets: The case of the M-star GJ 1214
Credit: eso.org
“Faculae can pose a problem if they are inhomogeneously distributed on the stellar surface. Using the eclipse mapping method, we study the distribution of the faculae on the surface of GJ 1214 using the Ca II H&K lines as tracers. In order to assess the homogeneity of the distribution in a quantitative way, we introduce the inhomogeneity factor IHF.”, said Eike Guenther (Thueringer Landessternwarte Tautenburg).
GJ 1214 is a red dwarf 47.8 light-years away from Earth. It has about 15% of the Sun’s mass and is much fainter than it. The effective temperature of GJ 1214 is about 3000 K. At a distance of about 0.014 AU it orbits GJ 1214 b, an exoplanet having the mass and diameter of a super-Earth.
