Flare Activity and UV Habitability in Extrasolar Planets

ABREVAYA, X. C.; CORTÓN, E.; MAUAS, P.J.D.

Conferencia; Extraterrestrial Life - Beyond our expectations?; 2012

Usually, dwarf M stars are targets in the search for extraterrestrial life outside of our solar system. They are choose among other stars because they are the most abudant in the galaxy, the liquid-water habitable zone (LW-HZ) is closer to these colder stars and it would be therefore easier to detect a terrestrial planet inside it. However, it is believed that planets in the LW-HZ should be tidally locked, which implies that this planetary body would have a hot face and a cold one, but recent atmospheric modeling provided evidences that the heat in the hot face could be transferred to the cold face. Furthermore there is another factor to analyze if planets around these stars in the LW-HZ could be suitable for life due flare activity in many of these stars (dMe stars), could have a strong impact over potential life beings. In particular in this work we analize the capability of UV-resistant microorganisms such as halophilic archaea, to survive the strong UV radiation characteristic of flare activity in dMe stars. Our results showed that the microorganisms can survive at the tested doses, showing that this kind of life could thrive in these extreme environments from the UV point of view.