Caracterização da atmosfera de exoplanetas do tipo hot-júpiters via espectrofotometria diferencial do trânsito

Abstract

Differential spectrophotometry of transiting Hot-J´upiters has shown to be a promising technique to characterize the upper atmosphere of these planets, without the necessity of spatially resolving it from its host star. The enhancement of this technique in the last decade allowed the achievement of transmission spectra in smaller telescopes, like the NOT 2.4m. Motivated by these results, this work aims to test the viability of characterizing exoplanetary atmospheres applying this technique in the 1.6m Perkin Elmer telescope, based in observations performed in OPD-LNA. The light curves obtained for the monitored objects showed a dispersion in the order of the transit depth, possibly generated by the oscillation of the objects in the slit together with unfavorable nights. Through the combination of the acquired spectra, it was possible to generate the transmission spectrum of the WASP-87b. The atmospheric models adjusted to the data indicate an oxygen-rich atmosphere (C/O < 1), with strong haze and evidence of TiO and VO absorber structures, which at temperatures above 2000K, suppress the Na and K absorption lines. This individual result is not enough to confirm the effectiveness of the method, and new observations must be made in order to better understand systemic errors and restrict the limits of its applicability