Search for disks in exoplanets host stars

C.SAFFE, M. GÓMEZ

La Plata

Congreso; 46 Reunión de la Asociación Argentina de Astronomía; 2003

Facultad de Ciencias Astronómicas y Geofícias de la UNLP - Asociación Argentina de Astronomía

We have assembled a database which comprises optical and infrared (IR) photometry of Exoplanet Host stars (EHs) and constructed the spectral energy distributions (SEDs) of these stars. We use several quantities to explore the existence of excess IR emission with respect to the photospheric level. In particular, Mannings & Barlow´s (1998, ApJ 497:330) criteria identify IR excess in 19-26% of the class V EH sources (6-8 out of 31). Several searches for Vega-like systems estimate a similar fraction of objects with IR excess emission, among main sequence stars. This excess emission is likely due to the presence of dust in circumstellar disks. We compare the polarization properties of the EHs and the Vega-like candidate objects and find one order of magnitude difference between the median polarization values for these groups. We interpret this result as a dissipation effect of the disk material due to planet/s formation.