Long-term chromospheric activity in dM Stars

MAUAS, P.J.D.

Porto, Portugal

Workshop; European Southern Observatory Workshop: Towards Other Earths; 2009

European Southern Observatory

Due to their low masses, dM stars are primary targets to search for terrestrial planets. However, they tend to be more active than earlier type stars, a fact which can hinder the detection of orbiting planets.On the other hand, most planets within the liquid water habitable zones around dM stars are probably tidally locked. Early arguments assumed that atmospheric volatiles would freeze in the dark side and boil off on the bright one. However, recent models predict that atmospheric heat transport could prevent freezing on the dark side of the planet. Therefore, it could be possible to have synchronously rotating planets where liquid water can exist (Joshi 2003, Tarter et al. 2007). However, UV radiation and stellar activity are other contrains to habitability to consider (Buccino et al. 2006, 2007).