How long can the most extreme planetary systems survive? - Measuring the tidal orbital decay of Hot Jupiters

Abstract

Hot Jupiters are a class of exoplanets, orbiting very close to their host stars. What is unusual about them is that gas planets are predicted to form beyond the snow line, a few astronomical units from their stars in the case of solar-like stars. Migration mechanisms like disc-driven migration or migration via dynamical processes can explain these short-period orbits. Due to the close distances between Hot Jupiters and their host stars, strong tidal forces lead to a transfer of angular momentum from the planet towards the star. This loss of angular momentum from the Hot Jupiter leads to their orbits shrinking slowly. Usually, the closer the orbit, the stronger the orbital decay. The timescales of these interactions are determined by the stellar tidal quality factor, which is only loosely constrained with estimates ranging over several magnitudes. By measuring the orbital decay of Hot Jupiters, the stellar tidal quality factor can be determined. In this project, we seek to determine the lifetime of Hot Jupiters and the tidal quality factor of their host stars using transit timing variations. This should give us an insight in how the stellar tidal quality factor might vary with for example the spectral type and also give implications for Hot Jupiter migration theories.