J/A+A/701/A240 HD 95338 CHEOPS light curves (Kalman+, 2025)
The CHEOPS view of HD 95338b:
Refined transit parameters, and a search for exomoons.
Kalman Sz., Simon A.E., Deline A., Csizmadia Sz., Szabo M.Gy.,
Ehrenreich D., Wilson T.G., Guenther M.N., Heitzmann A., Sousa S.G.,
Farnir M., Bonfanti A., Smith A.M.S., Pal A., Scandariato G., Adibekyan V.,
Brandeker A., Charnoz S., Akinsanmi B., Barros S.C., Alibert Y., Alonso R.,
Barczy T., Barrado Navascues D., Baumjohann W., Benz W., Billot N.,
Biondi F., Borsato L., Broeg C., Collier Cameron A., Corral van Damme C.,
Correia A.C.M., Cubillos P.E., Davies M.B., Deleuil M., Demangeon O.D.S.,
Demory B.-O., Derekas A., Edwards B., Egger J.A., Erikson A., Fortier A.,
Fossati L., Fridlund M., Gandolfi D., Gazeas K., Gillon M., Guedel M.,
Guterman P., Hasiba J., Helling C., Isaak K.G., Kiss L., Korth J.,
Lam K.W.F., Laskar J., Lecavelier des Etangs A., Leleu A., Lendl M.,
Magrin D., Maxted P.F.L., Merin B., Mordasini C., Munari M., Nascimbeni V.,
Olofsson G., Ottensamer R., Pagano I., Palle E., Peter G., Piazza D.,
Piotto G., Pollacco D., Queloz D., Ragazzoni R., Rando N., Rauer H.,
Ribas I., Santos N.C., Segransan D., Stalport M., Sulis S., Udry S.,
Ulmer B., Ulmer-Moll S., Van Grootel V., Venturini J., Villaver E.,
Walton N.A., Wolf S., Zingales T.
<Astron. Astrophys. 701, A240 (2025)>
=2025A&A...701A.240K 2025A&A...701A.240K (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry ; Optical
Keywords: methods: data analysis - techniques: photometric -
planets and satellites: individual: HD 95338b
Abstract:
Despite the ever-increasing number of known exoplanets, no uncontested
detections have been made of their satellites, known as exomoons.
The quest to find exomoons is at the forefront of exoplanetary
sciences. Certain space-born instruments are thought to be suitable
for this purpose. We show the progress made with the CHaracterizing
ExOPlanets Satellite (CHEOPS) in this field using the HD 95338
planetary system. We present a novel methodology as an important step
in the quest to find exomoons.
We utilised ground-based spectroscopic data in combination with Gaia
observations to obtain precise stellar parameters. These are then used
as input in the analysis of the planetary transits observed by CHEOPS
and the Transiting Exoplanet Survey Satellite (TESS). In addition, we
search for the signs of satellites primarily in the form of additional
transits in the Hill sphere of the eccentric Neptune-sized planet HD
95338b in a sequential approach based on four CHEOPS visits. We also
briefly explore the transit timing variations of the planet.
We present refined stellar and planetary parameters, narrowing down
the uncertainty on the planet-to-star radius ratio by a factor of 10.
We also pin down the ephemeris of HD 95338b. Using injection/retrieval
tests, we show that a 5σ detection of an exomoon would be
possible at RMoon=0.8R⊕ with the methodology presented here.
We exclude the transit of an exomoon in the system with
RMoon∼0.6R⊕ at the 1σ level. The algorithm used for
finding the transit-like event can be used as a baseline for other
similar targets, observed by CHEOPS or other missions.
Description:
The raw light curve was used Step 1 of Sect. 2.3 of the paper. The
detrended light curves are the output Step 4 of Sect. 2.3. The transit
parameters presented in the paper are calculated from the detrended
light curve. The two files have the same structure: time
(BJD_TDB-2457000), flux, flux error, exposure time, visit ID.
Objects:
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RA (2000) DE Designation(s)
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10 59 26.30 -56 37 22.9 HD 95338 = HIP 53719
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
detlc.dat 60 13438 HD 95338 detrended light curves
rawlc.dat 60 13580 HD 95338 raw light curves
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See also:
J/MNRAS/496/4330 : A 55-d period dense Neptune transiting HD 95338
(Diaz+, 2020)
Byte-by-byte Description of file: detlc.dat rawlc.dat
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Bytes Format Units Label Explanations
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1- 16 F16.11 d BJD Barycentruc Julian Date (TDB) of Observation
(BJD-2450000)
18- 35 F18.16 --- NFlux Normalized flux or relative intensity
36- 55 F20.18 --- e_NFlux Uncertainty on normalized flux
57- 58 I2 s ExpTime Exposure time of observations
60 I1 --- VisitID [1/4] Visit ID
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Acknowledgements:
Szilard Kalman, kalman.szilard(at)csfk.org
(End) Patricia Vannier [CDS] 16-Jul-2025