From Gaia to PLATO: two missions to understand exoplanets

Abstract

PLATO mission will detect terrestrial-type exoplanets orbiting in the habitable zone of solar-like stars and characterise their properties. Aims. This work analyzes Gaia Data Release 2 data with two main goals in mind. First, to study the stellar populations that PLATO will be able to detect in the currently proposed observation fields and evaluate the contribution of sources fainter than the PLATO limiting magnitude, which will contribute to its background level. On the other hand, this work will also allow to update the Gaia performances model to be implemented in the Gaia Object Generator (GOG). Methods. We use the Gaia Archive interface to obtain the data of the proposed PLATO fields. With the help of Topcat we can analize them. In order to derive PLATO's background and update Gaia performances, we reduce the amount of data computing running medians with a Python code, fitting then the results with Gnuplot. Results. The solar-type stars, F5 to K7 type, interesting for PLATO in the search for exoplanets are the most numerous in both proposed fields of study. The mean background level found in this work is 25.6546 mag/arcsec2 for SPF and 25.3656 mag/arcsec2 for NPF. The derived performance model fits better with GDR2's G errors, specially for low G, and will be implemented in GOG.