Astrophysical false positives in exoplanet transit surveys: why do we need bright stars ?

TL;DR

This paper reviews the challenge of astrophysical false positives in exoplanet transit surveys, emphasizing the importance of bright stars and how upcoming missions like PLATO 2.0 and TESS can reduce false positives.

Contribution

It provides a comprehensive review of false positives in transit surveys, compares false-positive rates of Kepler and CoRoT, and discusses the advantages of observing bright stars with future missions.

Findings

PLATO 2.0 expected to have fewer false positives than Kepler

False-positive rates vary between different transit surveys

Bright star observations are crucial for reducing false positives

Abstract

Astrophysical false positives that mimic planetary transit are one of the main limitation to exoplanet transit surveys. In this proceeding, we review the issue of the false positive in transit survey and the possible complementary observations to constrain their presence. We also review the false-positive rate of both Kepler and CoRoT missions and present the basics of the planet-validation technique. Finally, we discuss the interest of observing bright stars, as PLATO 2.0 and TESS will do, in the context of the false positives. According to simulations with the Besan\c{c}on galactic model, we find that PLATO 2.0 is expected to have less background false positives than Kepler, and thus an even lower false-positive rate.