Phase curve and geometric albedo of WASP-43b measured with CHEOPS, TESS, and HST WFC3/UVIS

Scandariato, G.; Singh, V.; Kitzmann, D.; Lendl, M.; Brandeker, A.; Bruno, G.; Bekkelien, A.; Benz, W.; Gutermann, P.; Maxted, P. F. L.; Bonfanti, A.; Charnoz, S.; Fridlund, M.; Heng, Kevin; Hoyer, S.; Pagano, I.; Persson, C. M.; Salmon, S.; Van Grootel, V.; Wilson, T. G.; ... (2022). Phase curve and geometric albedo of WASP-43b measured with CHEOPS, TESS, and HST WFC3/UVIS. Astronomy and astrophysics, 668, A17. EDP Sciences 10.1051/0004-6361/202243974

[img]
Preview
Text
aa43974-22.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (12MB) | Preview

Context. Observations of the phase curves and secondary eclipses of extrasolar planets provide a window onto the composition and thermal structure of the planetary atmospheres. For example, the photometric observations of secondary eclipses lead to the measurement of the planetary geometric albedo, Ag, which is an indicator of the presence of clouds in the atmosphere.

Aims. In this work, we aim to measure the Ag in the optical domain of WASP-43b, a moderately irradiated giant planet with an equilibrium temperature of ~1400 K.

Methods. For this purpose, we analyzed the secondary eclipse light curves collected by CHEOPS together with TESS along with observations of the system and the publicly available photometry obtained with HST WFC3/UVIS. We also analyzed the archival infrared observations of the eclipses and retrieve the thermal emission spectrum of the planet. By extrapolating the thermal spectrum to the optical bands, we corrected for the optical eclipses for thermal emission and derived the optical Ag.

Results. The fit of the optical data leads to a marginal detection of the phase-curve signal, characterized by an amplitude of 160 ± 60 ppm and 80−50+60 ppm in the CHEOPS and TESS passbands, respectively, with an eastward phase shift of ~50° (1.5σ detection). The analysis of the infrared data suggests a non-inverted thermal profile and solar-like metallicity. The combination of the optical and infrared analyses allows us to derive an upper limit for the optical albedo of Ag< 0.087, with a confidence of 99.9%.

Conclusions. Our analysis of the atmosphere of WASP-43b places this planet in the sample of irradiated hot Jupiters, with monotonic temperature-pressure profile and no indication of condensation of reflective clouds on the planetary dayside.

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:

Kitzmann, Daniel, Benz, Willy, Heng, Kevin, Gambicorti, Lisa, Alibert, Y., Beck, Thomas, Broeg, Christopher, Demory, Brice-Olivier Denys, Fortier, A., Thomas, Nicolas

Subjects:

500 Science > 530 Physics
500 Science > 520 Astronomy
600 Technology > 620 Engineering

ISSN:

0004-6361

Publisher:

EDP Sciences

Language:

English

Submitter:

Danielle Zemp

Date Deposited:

10 Mar 2023 09:22

Last Modified:

10 Mar 2023 23:26

Publisher DOI:

10.1051/0004-6361/202243974

BORIS DOI:

10.48350/179718

URI:

https://boris.unibe.ch/id/eprint/179718

Actions (login required)

Edit item Edit item
Provide Feedback