P11E-08
The Interaction of Venus-like, M-dwarf Planets with the Stellar Wind of Their Host Star
Monday, 14 December 2015: 09:45
2007 (Moscone West)
Ofer Cohen1, Alex Glocer2, Jeremy J Drake1, Yingjuan Ma3, Jared Micheal Bell4, Cecilia Garraffo1 and Tamas I Gombosi5, (1)Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, United States, (2)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (3)University of California Los Angeles, Los Angeles, CA, United States, (4)National Institute of Aerospace, Yorktown, VA, United States, (5)Univ of Michigan, Ann Arbor, MI, United States
Abstract:
We study the interaction between the atmospheres of Venus-like, non-magnetized exoplanets orbiting an M-dwarf star, and the stellar wind using a multi-species MHD model. We focus our investigation on the effect of enhanced stellar wind and enhanced EUV flux as the planetary distance from the star decreases. Our simulations reveal different topologies of the planetary space environment for sub- and super-Alfvénic stellar wind conditions, which could lead to dynamic energy deposition into the atmosphere during the transition along the planetary orbit. We find that the stellar wind penetration for non-magnetized planets is very deep, up to a few hundreds of kilometers. We estimate a lower limit for the atmospheric mass-loss rate and find that it is insignificant over the lifetime of the planet. However, we predict that when accounting for atmospheric ion acceleration, a significant amount of the planetary atmosphere could be eroded over the course of a billion years.
