Fundamental properties and evolution of exoplanets and their host stars

UoM administered thesis: Master of Science by Research

  • Authors:
  • Mazin Nasralla

Abstract

This work had two objectives. The first was to derive a program that could, at the push of a button, generate an extended series of accurate stellar properties from a limited range of observations. The second was to take these estimates and use them to derive some meaningful insight into the properties of their planets. The mass, age and surface gravity of 196 planet-hosting stars were derived from prior observations of luminosity, effective temperature and metallicity. The study generated a mean error in log of 0.05 dex, comparable with measurements derived from spectroscopy. The model was able to constrain stellar age to a mean of 2.56 Gyr. Such was the accuracy and precision of the results that it allowed reporting errors in the discovery literature to be found. The derived host-star properties were used to model the current and future evolution of the stellar sample, and the orbital evolution of its planets under a tidal regime taken from the literature. The tidal model generated migration rates at the low end of predicted literature values, but they were still significant enough to generate engulfments of some hot-Jupiter planets in their star's main-sequence lifetime. The tidal effect was particularly pronounced around evolved stars. A correlation between the current modelled migration rate and the stellar spin-rate was established for hot-Jupiters within 0.04 AU of their stars.

Details

Original languageEnglish
Awarding Institution
Supervisors/Advisors
Award date1 Aug 2020