High-precision multiwavelength eclipse photometry of the ultra-hot gas giant exoplanet WASP-103 b

Delrez, L; Madhusudhan, N; Lendl, M; Gillon, M; Anderson, D R; Neveu-VanMalle, M; Bouchy, F; Burdanov, A; Collier-Cameron, A; Demory, Brice-Olivier; 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, 474(2), pp. 2334-2351. Oxford University Press 10.1093/mnras/stx2896

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We present 16 occultation and three transit light curves for the ultra-short period hot Jupiter WASP-103b, in addition to five new radial velocity measurements. We combine these observations with archival data and perform a global analysis of the resulting extensive data set, 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 (6.4σ) and 3567+⁴⁰⁰−₃₅₀ ppm (10.2σ), respectively. We use these two measurements, together with recently published HST/WFC3 data, to derive joint constraints on the properties of WASP-103b'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, in both emission and transmission, are required to better constrain the atmospheric properties of WASP-103b.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences
08 Faculty of Science > Physics Institute
10 Strategic Research Centers > Center for Space and Habitability (CSH)
08 Faculty of Science > Physics Institute > NCCR PlanetS

UniBE Contributor:

Demory, Brice-Olivier

Subjects:

500 Science > 520 Astronomy
500 Science > 530 Physics

ISSN:

0035-8711

Publisher:

Oxford University Press

Language:

English

Submitter:

Danielle Zemp

Date Deposited:

29 May 2019 17:12

Last Modified:

29 May 2019 17:26

Publisher DOI:

10.1093/mnras/stx2896

BORIS DOI:

10.7892/boris.126815

URI:

https://boris.unibe.ch/id/eprint/126815

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