An improved model for the upper atmosphere of EpsilonEridani

MARIELA C. VIEYTES; JUAN I. PERALTA

Rosario

Congreso; Reunión Anual de la Asociación Argentina de Astronomía; 2020

Facultad de Ciencias Exactas, Ingeniería Agrimensura, UNR

The photochemistry and composition of the atmosphere of a planet orbiting a star in its habitablezone is critically influenced by the near and far UV radiation emitted by the host star. In particular, the extremeUV and X-rays photons can drive atmospheric mass loss. At the present some regions of the UV spectra areunobservable due to interstellar absorption, and for the characterization of the UV radiation environment arounda planet, a reliable atmospheric stellar model for the host star is needed. In this work we present an initial stellarmodel for the upper atmosphere of the dK2V star, Epsilon Eridani. Here we extend our previous photosphere?chromosphere model that accurately reproduced the visible continuum and several important spectral featuresobserved at CASLEO. In order to build the upper part of our model corresponding to the transition region andcorona, we use HST and XMM data obtained as part of the MUSCLES (Measurements of the Ultraviolet SpectralCharacteristics of Low-mass Exoplanetary Systems) survey. The use of this new model, that takes in account thecomplete stellar atmosphere from the phostosphere to the corona, allows us to obtain a reliable calculation of theradiation received by the planet.