Photometric modulation in stars with planets detected by the TESS space mission

• Grant number: 24/18377-8
• Support Opportunities: Scholarships in Brazil - Program to Stimulate Scientific Vocations
• Start date: January 20, 2025
• End date: March 11, 2025
• Field of knowledge: Physical Sciences and Mathematics - Astronomy
• Principal Investigator: José Renan de Medeiros
• Grantee: Gabriel Felipe Mendes de Brito e Gonzalez
• Host Institution: Centro de Ciências Exatas e da Terra (CCET). Universidade Federal do Rio Grande do Norte (UFRN). Natal , SP, Brazil

Abstract

The search for exoplanets is today one of the frontier topics in astronomy, especially given the prospect of discovering Earth-like planets. As of 10/10/2024, 7339 exoplanets have been discovered [1], including 1278 detected via radial velocity (spectroscopic technique) and 4464 via planetary transit (photometric technique), orbiting mainlystars of spectral types F, G and K. Some physical features are common to most known exoplanets, as well as their host stars, where most of these are main sequence stars, with spectral classes similar to or close to our own Sun. Most known exoplanets are quite massive, but this is not This means that there are no Earth-sized exoplanets. In reality, it is current detection methods that favor the discovery of massive planets orbiting close to their host stars. Unlike the nearly circular orbits of the planets in the Solar System, most exoplanets exhibit largely eccentric orbits. Most known exoplanets are gaseous, similar to the giant planets of the Solar System, although some of the smaller exoplanets found show signs of terrestrial, i.e. rocky, compositions.Despite the great advances in Exoplanetology, there are a significant number of fundamental questions still unanswered, including the very existence of planets with habitable conditions, whether orbiting stars identical to the Sun or not. Among other aspects, in addition to the biochemical composition of the planetary atmosphere, it is essential to know the behavior of gravitational and magnetic interactions between stars and their planets, a determining factor for the existence of conditions for biological activity on a planet [2][3].Another issue of great relevance concerns the fact that the fraction of planets detected around M dwarf stars is still very low, although planetary transits are more easily detected around these stars. With the advent of space missions such as TESS[4] and the James Webb Space Telescope (JWST)[5], it is finally possible to expand the frontiers of Exoplanetology to the region of cold dwarf stars, which will enable, among other aspects, an expansion in the our knowledge of planetary atmospheres. In particular, planets in the habitable zones of M stars have short orbital periods, which makes them good laboratories for quickly determining their physical parameters using dedicated spectrometers operating in the infrared, such as the NIRPS Near Infrared Planet Searcher). The central problem of the present proposal is the search for photometric modulations in Light Curves (Time Series) of stars, of spectral type M, hosts of planets detected via planetary transit by the TESS Space Mission, with an emphasis on planets located in Habitability Zones. Such modulations can reveal signatures of rotation, pulsation, stellar oscillation and magnetic activity, which are fundamental phenomena in defining the habitability conditions around a star. For this purpose, the Student will analyze light curves collected by the TESS satellite, applying a manifold computational procedure, composed of the Lomb-Scargle, Fast Fourier and Wavelet Transforms[6].References[1] http://exoplanet.eu/[2] Canto Martins et al. 2023, Nature Astronomy, 7, p. 900-904.[3] Messias et al. 2023, ApJ, 930, L23.[4] Ricker, G. R., Winn, J. N., Vanderspek, R., et al. 2015, JATIS, 1, 014003.[5] Gardner, J. P., Mather, J. C., Clampin, M. et al. 2006, ExA, 123, 485.[6] Canto Martins et al. 2020, ApJS, 250, 20. (AU)