ARES. II. Characterizing the Hot Jupiters WASP-127 b, WASP-79 b, and WASP-62b with the Hubble Space Telescope*

Abstract

This paper presents the atmospheric characterization of three large, gaseous planets: WASP-127 b, WASP-79 b, and WASP-62 b. We analyzed spectroscopic data obtained with the G141 grism (1.088-1.68 μm) of the Wide Field Camera 3 on board the Hubble Space Telescope using the Iraclis pipeline and the TauREx3 retrieval code, both of which are publicly available. For WASP-127 b, which is the least dense planet discovered so far and is located in the shortperiod Neptune desert, our retrieval results found strong water absorption corresponding to an abundance of log(H 2 O)=−2.71-+ 1.05 0.78 and absorption compatible with an iron hydride abundance of log(FeH)=-+ 5.25 1.10 0.88 , with an extended cloudy atmosphere. We also detected water vapor in the atmospheres of WASP-79 b and WASP-62 b, with best-fit models indicating the presence of iron hydride, too. We used the Atmospheric Detectability Index as well as Bayesian log evidence to quantify the strength of the detection and compared our results to the hot Jupiter population study by Tsiaras et al. While all the planets studied here are suitable targets for characterization with upcoming facilities such as the James Webb Space Telescope and Ariel, WASP-127 b is of particular interest due to its low density, and a thorough atmospheric study would develop our understanding of planet formation and migration. Unified Astronomy Thesaurus concepts: Exoplanet astronomy (486); Exoplanet atmospheres (487); Astronomy data analysis (1858); Hubble Space Telescope (761)

KELT-11 b: Abundances of Water and Constraints on Carbon-bearing Molecules from the Hubble Transmission Spectrum

“…Thus, identification of a near-visible absorber and/or its precise abundance is likely to be biased by systematic offsets when TES and HST is used. Finally, most of our retrievals recover a well-defined temperature around 1300 K, which is expected from previous transit observations (Tsiaras et al 2018;Caldas et al 2019;MacDonald et al 2020;Skaf et al 2020). However, this disagrees with the findings from Colón et al (2020), which find a lower limit on the temperature of about 1900 K. These differences could either be due to the use of different reduction/retrieval pipelines or differences in the choice of models (temperature/clouds).…”

“…In our full retrieval we also consider the absorption from the optical absorbers: TiO, VO, and FeH. Evidence for these has been presented in a number of previous HST G141 transmission studies (e.g., Edwards et al 2020a;Skaf et al 2020). The obtained log E is higher than with previous models, however it still remains in the same range of evidence: the difference with the water-only model is only 2.4.…”

“…The recovered temperature is about 1300 K, which is expected since the observations are probing the terminator region, which is naturally colder than the dayside of the planet, better represented by the equilibrium temperature of about 1700 K. Many studies pointed out that these observed differences between equilibrium and terminator temperatures, which are observed for almost all planets (Tsiaras et al 2018;Skaf et al 2020), could be caused by three-dimensional biases not accounted for in one-dimensional models (Feng et al 2016 Contrary to suggestions by Zǎk et al (2019), the retrieval presented here indicates a relatively clear atmosphere and does not recover evidence of high-altitude clouds. We constrain the top pressure for the clouds to be P c 0.1 bar.…”

WASP-117 b: An Eccentric Hot Saturn as a Future Complex Chemistry Laboratory

“…In recent years the Hubble and Spitzer Space Telescopes have enabled the study of an increasing number of exoplanetary atmospheres through transit, eclipse, or phase-curve spectrophotometric observations (e.g., Vidal-Madjar et al 2003;Swain et al 2008;Laughlin et al 2009;Linsky et al 2010;Tinetti et al 2010;Majeau et al 2012;Deming et al 2013;Fraine et al 2014;Stevenson et al 2014c;Morello et al 2016;Evans et al 2017;Edwards et al 2020a;Skaf et al 2020). Complementary observations from the ground, through high-dispersion or directimaging spectroscopic techniques, have allowed for the extension of atmospheric observations to nontransiting planets (e.g., Brogi et al 2012;Macintosh et al 2015).…”

ARES. III. Unveiling the Two Faces of KELT-7 b with HST WFC3*

“…These are generally attributed to the presence of optical absorbers such as titanium oxide (TiO), vanadium oxide (VO), or iron hydride (FeH). These planets include WASP-121b (Mikal-Evans et al 2019) and WASP-127 b (Skaf et al 2020). Additionally, high-resolution ground-based observations have detected the presence of a variety of heavy metals in the atmosphere of KELT-9 b (Hoeijmakers et al 2019) while lower resolution data were used to claim the presence of aluminum oxide (AlO) in WASP-33 b (von Essen et al 2019).…”