HD 95338 CHEOPS light curves

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 5{sigma} detection of an exomoon would be possible at R_Moon_=0.8R_{Earth}_ with the methodology presented here.

We exclude the transit of an exomoon in the system with R_Moon_~0.6R_{Earth}_ at the 1{sigma} 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.