High-precision multiwavelength eclipse photometry of the ultra-hot gas giant exoplanet WASP-103 b
Abstract
We present sixteen occultation and three transit light curves for theultra-short period hot Jupiter WASP-103 b, in addition to five newradial velocity measurements. We combine these observations with archival data and perform a global analysis of the resulting extensive dataset, accounting for the contamination from a nearby star. We detect the thermal emission of the planet in both the z' and KS-bands, the measured occultation depths being 699 ± 110 ppm (6.4-σ) and 3567_{-350}^{+400} ppm (10.2-σ), respectively. We use these two measurements together with recently published HST/WFC3 data to derive joint constraints on the properties of WASP-103 b's dayside atmosphere. On one hand, we find that the z'-band and WFC3 data are best fit by an isothermal atmosphere at 2900 K or an atmosphere with a low H2O abundance. On the other hand, we find an unexpected excess in the KS-band measured flux compared to these models, which requires confirmation with additional observations before any interpretation can be given. From our global data analysis, we also derive a broad-band optical transmission spectrum that shows a minimum around 700 nm and increasing values towards both shorter and longer wavelengths. This is in agreement with a previous study based on a large fraction of the archival transit light curves used in our analysis. The unusual profile of this transmission spectrum is poorly matched by theoretical spectra and is not confirmed by more recent observations at higher spectral resolution. Additional data, both in emission and transmission, are required to better constrain the atmospheric properties of WASP-103 b.
Citation
Delrez , L , Madhusudhan , N , Lendl , M , Gillon , M , Anderson , D R , Neveu-VanMalle , M , Bouchy , F , Burdanov , A , Collier-Cameron , A , Demory , B-O , Hellier , C , Jehin , E , Magain , P , Maxted , P F L , Queloz , D , Smalley , B & Triaud , A H M J 2018 , ' High-precision multiwavelength eclipse photometry of the ultra-hot gas giant exoplanet WASP-103 b ' , Monthly Notices of the Royal Astronomical Society , vol. 474 , no. 2 , pp. 2334-2351 . https://doi.org/10.1093/mnras/stx2896
Publication
Monthly Notices of the Royal Astronomical Society
Status
Peer reviewed
ISSN
0035-8711Type
Journal article
Rights
© 2017, the Author(s). This work has been made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1093/mnras/stx2896
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