Thesis

Small planets around small stars: characterizing M-dwarfs in CHEOPS

• Call:

  IDPASC Portugal - PHD Programme 2017

• Academic Year:

  2017 / 2018

• Domain:

  Astrophysics

• Supervisor:

  Sérgio Sousa

• Co-Supervisor:

• Institution:

  Universidade do Porto

• Host Institution:

  Instituto de Astrofísica e Ciências do Espaço

• Abstract:

  This project will be focused on the precise characterization of low mass stellar/planetary systems observed with CHEOPS. The characterization of the planets in these systems are strongly dependent on the correct knowledge of the host stars. Therefore the goal of this topic is strongly connected with the precise characterization of M stars. Although these cool M stars are the most common stars in our Galaxy they still represent an outstanding challenge in what regards their characterization and are currently the most crucial step for an accurate study of low mass stellar/planetary systems. To achieve this goal we will use ground-breaking spectroscopic analysis of near-infra-red (NIR) spectra of M-dwarf stars with the goal of deriving precise and homogeneous stellar parameters. The knowledge of the stellar parameters of planet-hosts, in particular their radii, is essential for the derivation of the properties of the discovered planets. The goals of the present project will have important impact in the scientific community and are of great importance for the full success of future space missions like CHEOPS for which we have direct access to private/consortium data (80% of the telescope time), but also for TESS, which will have immediate public data, and later for PLATO. With this in mind, the goal of the proposed project is to use methodologies for the spectroscopic analysis of near-IR high resolution spectra that are/will soon be available from new instruments such as SpiRou, CARMENES, and CRIRES+. Moreover, we intend to develop a method based on spectral synthesis that could be used as an alternative for this kind of stars. These methods will be applied to M stars hosting planets observed with CHEOPS/TESS. Besides the determination of precise stellar (and thus planetary) properties, one side important side project will be to further explore possible correlations between the properties of the stars and the presence of the planets, which can give important clues for planet formation models.