Thesis

Looking for rings and tides in transiting planets

• Call:

  IDPASC Portugal - PHD Programme 2017

• Academic Year:

  2017 / 2018

• Domain:

  Astrophysics

• Supervisor:

  Susana Barros

• Co-Supervisor:

  Nuno Santos

• Institution:

  Universidade do Porto

• Host Institution:

  CAUP

• Abstract:

  Recent years have seen a revolution in our knowledge of exoplanetary systems including many surprising discoveries. In contrast, several expected results have not yet been observed or confirmed. Among these is the existence of moons and rings, as well as of tidal deformations of the exoplanets that orbit very close to their parent star. This project aims at detecting these extreme systems taking advantage of the unprecedented precision of the ongoing and future transit missions K2, TESS, CHEOPS and Plato, as well as of new high-resolution spectrographs such as ESPRESSO. Our team is now particularly involved in the CHEOPS (ESA) mission, to be launched in 2018. CHEOPS (CHarecterising ExOplanets Satellite) is a new ESA mission that will allow to observe key bright targets with extreme characteristics. The development of CHEOPS is also intimately related to our strong participation in the ESPRESSO (ESO) high-resolution spectrograph for the VLT telescopes. ESPRESSO will allow deriving radial velocity measurements with an unprecedented precision, and hence it will permit to measure masses for the smallest known exoplanets. Together, CHEOPS and ESPRESSO will give us a unique opportunity to characterize the properties (mass, radius, composition, structure, shape) of exoplanets. In particular, in this project we propose to upgrade a state of the art Bayesian transit and radial velocity fitting code to include rings, planetary occultations, Rossiter-McLaughlin effect, and tidal effects. Rings have never been detected around extra-solar planets, but their signature should be present in both the transit light and radial-velocity curves (through Rossiter-McLaughlin effect). The tidal star-planet interactions deform the planets, producing also significant deformation in the light curve (never detected, but expected for some short period planets). Hence, the code will allow searching for the signature of rings, planetary occultations, and tidal effects. All these effects have been predicted by theory but they were never observed: the new set of instruments will allow us to make a breakthrough in this domain. Our team has privileged access to Cheops data hence the student will be able to access this unique dataset. Furthermore, the tools developed during this project we may also use for other datasets: NASA K2, TESS missions and in the future for ESA PLATO mission. The results of this project will increase the scientific exploitation of these state of the art missions and lead to a better understanding of planetary systems.