| Issue |
A&A
Volume 677, September 2023
|
|
|---|---|---|
| Article Number | L12 | |
| Number of page(s) | 4 | |
| Section | Letters to the Editor | |
| DOI | https://doi.org/10.1051/0004-6361/202347704 | |
| Published online | 12 September 2023 | |
Letter to the Editor
Stellar obliquity and planetary albedo in HAT-P-32
Derived from the TESS light curve
1
Thüringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany
e-mail: sczesla@tls-tautenburg.de
2
Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
Received:
11
August
2023
Accepted:
28
August
2023
HAT-P-32 is an exceptional planetary system. Its active F-type host star is orbited by a hot Jupiter, the evaporation of which produces a giant structure of tidal tails. We analyze the light curve of HAT-P-32 obtained by the Transiting Exoplanet Survey Satellite (TESS) and find a secondary eclipse superimposed on photometric modulation likely caused by stellar rotation. We estimate a secondary eclipse depth of (1.4 ± 0.4)×10−4. Adopting a prior of 1962 ± 83 K for the effective planetary dayside temperature yields values of 0.16 ± 0.07 for the geometric albedo and an associated estimate of 0.46 ± 0.21 for the circulation efficiency of HAT-P-32 b, which favor a dark and windy scenario for the atmosphere. Our analysis of the photometric modulation yields a stellar rotation period of 2.974 ± 0.004 d, implying a value of 79° for the inclination of the stellar rotation axis with a 95% credible interval from 70° to 88°. This constraint further allows us to estimate a value of (84.9 ± 1.5)° for the three-dimensional obliquity. Despite showing an almost polar planetary orbit, the host star is, therefore, seen nearly equator on.
Key words: planets and satellites: atmospheres / techniques: photometric / planets and satellites: individual: HAT-P-32
© The Authors 2023
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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