IAFE   05512
INSTITUTO DE ASTRONOMIA Y FISICA DEL ESPACIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The EXO-UV project
Autor/es:
ABREVAYA, X.C.
Lugar:
Saclay
Reunión:
Workshop; Star Planet Interactions and the Habitable Zone; 2014
Resumen:
Stellar radiation has an essential role in planetary habitability, since the radiation received from the parent star can influence planetary evolution, its atmosphere, and can determine the conditions for the origin, evolution and existence of life in a planetary body. These effects can be beneficial or detrimental depending mainly on the kind (wavelength) and flux of radiation received on the planetary surface. Additionally, the effects of radiation on life will also depend on the ability of life forms to cope with these levels of radiation. In particular, non-ionizing radiation emissions related to UV wavelengths can be a constraint for life but it has also been postulated as a driving force for biological evolution. Moreover, UV radiation can play a role in photochemical reactions that are produced at atmospheric level and can act as an energy source for polymerization/destruction of prebiotic molecules. Several works have analyzed the influence UV radiation fluxes in F, G, K, and M stars in order to determine their suitability for life (e.g: Cockell, 1999, Cuntz et al., 2010). However, it is necessary to perform laboratory simulations to test the theoretical predictions that have been made. Additionally, there is a lack of data about radiation emission fluxes in different stellar astrophysical contexts considering particular planetary and atmospheric conditions. The main objective of this project is to study and characterize radiation environments of F, G, K and M stars in the context of exoplanets (Earth-like planets) to determine if these environments would support life, since radiation can act as a limiting factor for the development and evolution of life. In particular this project has two main goals: 1) The development of software that allows to obtain corrected UV flux values from data belonging to different main sequence stars (F,G,K,M), using as data source measurements made by the International Ultraviolet Explorer (IUE) and the Hubble Space Telescope (HST), served by the MAST archive. The aforementioned data sources provide spectral data that, once corrected for several parameters, allows a good estimation of the UV flux a planet would receive. This will include fluxes on the quiescent state of the star but it could also be expanded to the analysis of flares in some of these stars. 2) The modelling of the atmospheres considering the atmospheric features of the planets to obtain the UV fluxes over the surface of the exoplanets. 3) The simulation of these radiation environments under laboratory conditions to perform biological experiments with microorganisms (UV, 200-400nm range), in particular radiation resistant microorganisms (Abrevaya et al, 2011a,b). This project seeks to expand previous work, considering significant amount of data and laboratory simulations of these extraterrestrial environments. This could provide some important insights about planetary habitability, increasing our knowledge about the capacity of life to survive in the context of exoplanets and stars of different spectral types. References: Abrevaya X.C. et al 2011a Proc. IAU 286, 405 Abrevaya X.C. et al 2011b Astrobiology11, 1034 Cockell C.S. 1999 Icarus 141, 399 Cuntz, M. et al 2010 Proc. IAU 264,1 El listado de resumenes puede verse publicado en la página: http://irfu.cea.fr/habitability/