J/A+A/686/A282 CHEOPS light curves of HD 15337 (TOI-402) (Rosario+, 2024)
Precise characterisation of HD 15337 with CHEOPS:
A laboratory for planet formation and evolution.
Rosario N.M., Demangeon O.D.S., Barros S.C.C., Gandolfi D., Egger J.A.,
Serrano L.M., Osborn H.P., Beck M., Benz W., Floren H.-G., Guterman P.,
Wilson T.G., Alibert Y., Fossati L., Hooton M.J., Delrez L., Santos N.C.,
Sousa S.G., Bonfanti A., Salmon S., Adibekyan V., Nigioni A., Venturini J.,
Alonso R., Anglada G., Asquier J., Barczy T., Barrado Navascues D.,
Barragan O., Baumjohann W., Beck T., Billot N., Biondi F., Bonfils X.,
Borsato L., Brandeker A., Broeg C., Cessa V., Charnoz S.,
Collier Cameron A., Csizmadia Sz., Cubillos P.E., Davies M.B., Deleuil M.,
Deline A., Demory B.-O., Ehrenreich D., Erikson A., Esposito M., Fortier A.,
Fridlund M., Gillon M., Guedel M., Guenther M.N., Helling C., Hoyer S.,
Isaak K.G., Kiss L.L., Lam K.W.F., Laskar J., Lecavelier des Etangs A.,
Lendl M., Luntzer A., Magrin D., Maxted P.F.L., Mordasini C., Nascimbeni V.,
Olofsson G., Osborne H.L.M., Ottensamer R., Pagano I., Palle E., Peter G.,
Piotto G., Pollacco D., Queloz D., Ragazzoni R., Rando N., Rauer H.,
Ribas I., Scandariato G., Segransan D., Simon A.E., Smith A.M.S.,
Stalport M., Szabo Gy.M., Thomas N., Udry S., Van Eylen V., Van Grootel V.,
Villaver E., Walter I., Walton N.A.
<Astron. Astrophys. 686, A282 (2024)>
=2024A&A...686A.282R 2024A&A...686A.282R (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry ; Optical
Keywords: techniques: photometric - techniques: radial velocities -
planets and satellites: composition - stars: individual: HD15337 -
stars: individual: TOI-402 - stars: individual: TIC-12089692
Abstract:
The HD 15337 (TIC 120896927, TOI-402) system was observed by the
Transiting Exoplanet Survey Satellite (TESS), revealing the presence
of two short-period planets situated on opposite sides of the radius
gap. This offers an excellent opportunity to study theories of
formation and evolution, as well as to investigate internal
composition and atmospheric evaporation.
We aim to constrain the internal structure and composition of two
short-period planets situated on opposite sides of the radius valley:
HD 15337 b and c. We use new transit photometry and radial velocity
data.
We acquired 6 new transit visits with the CHaracterising ExOPlanet
Satellite (CHEOPS) and 32 new radial velocity measurements from the
High Accuracy Radial Velocity Planet Searcher (HARPS) to improve the
accuracy of the mass and radius estimates for both planets. We
re-analysed the light curves from TESS sectors 3 and 4 and analysed
new data from sector 30, correcting for long-term stellar activity.
Subsequently, we performed a joint fit of the TESS and CHEOPS light
curves, along with all available RV data from HARPS and the Planet
Finder Spectrograph (PFS). Our model fit the planetary signals,
stellar activity signal, and instrumental decorrelation model for the
CHEOPS data simultaneously. The stellar activity was modelled using a
Gaussian-process regression on both the RV and activity indicators.
Finally, we employed a Bayesian retrieval code to determine the
internal composition and structure of the planets.
We derived updated and highly precise parameters for the HD 15337
system. Our improved precision on the planetary parameters makes HD
15337 b one of the most precisely characterised rocky exoplanets, with
radius and mass measurements achieving a precision better than 2% and
7%, respectively. We were able to improve the precision of the radius
measurement of HD 15337 c to 3%. Our results imply that the
composition of HD 15337 b is predominantly rocky, while HD 15337 c
exhibits a gas envelope with a mass of at least 0.01M⊕.
Our results lay the groundwork for future studies, which can further
unravel the atmospheric evolution of these exoplanets and offer new
insights into their composition and formation history as well as the
causes behind the radius gap.
Description:
We present the 6 transit light curves of HD 15337 (TIC 120896927,
TOI-402) obtained by CHEOPS: the reduced raw data and the detrended
curves. The reduced original data can be obtained from DACE and the
CHEOPS public archive.
Objects:
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RA (2000) DE Designation(s)
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02 27 28.38 -27 38 06.74 HD 15337 = TOI-402
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
lccorr.dat 59 3976 Detrended CHEOPS photometry of HD 15337
lcraw.dat 59 3976 Raw CHEOPS photometry of HD 15337
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See also:
J/A+A/627/A43 : Two super-Earths orbiting TOI-402 (Dumusque+, 2019)
Byte-by-byte Description of file: lccorr.dat lcraw.dat
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Bytes Format Units Label Explanations
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1- 23 F23.15 d BJD Barycentric Julian Date (BJD)
25- 41 F17.15 --- Flux Normalized flux
43- 59 F17.15 --- e_Flux Normalized flux error
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Acknowledgements:
Nuno Rosario, nuno.rosario(at)astro.up.pt
(End) Patricia Vannier [CDS] 10-Apr-2024