Exoplanetary atmospheres: the importance of the determination of precise orbital parameters for their atmospheric characterization.

MICULÁN, R.; TORRES, A. F.; VON ESSEN, C.

La Serena

Congreso; Second Binational Meeting AAA-SOCHIAS; 2018

Since the first detection of an exoplanet orbiting a sun-like star in 1995 (Mayor & Queloz, 1995) thousands of exoplanets have been discovered by ground and space-based observatories. The number of discoveries is in continuous growth, so the scientific challenge today is to characterize them in detail. During primary transits, the light of the star is absorbed or not by the exoplanet atmosphere, depending on its compounds. Thus, when the planetary atmosphere absorbs the starlight, the planet looks larger than compared to a planet with an atmosphere not interacting. In consequence this absorption translates into a variation of Rp /Rs (Rp ,Rs : planet and star radius respectively) as a function of wavelength. Thanks to this variation, measuring the absorption (i.e., the transit depth) as a function of wavelength, it is possible to infer the chemical composition of the atmosphere of the transiting planet. However, since this variation is small (∼ 1% for hot Jupiters) and the orbital parameters are correlated, it is necessaryto have these parameters determined as accurate as possible. Here, we present the refined orbital parameters, derived from transit light curvesobserved with Argentinian telescopes, of a group of systems that we have identified as strong candidates for our future exo-atmospheric studies.