摘要：Stellar activity is one of the main obstacles to high-precision exoplanet observations and has motivated extensivestudies in detection and characterization problems. Most efforts focused on unocculted starspots in optical transitspectrophotometry, while the impact of starspot crossings is assumed to be negligible in the near-infrared. Here, wepresent HST/WFC3 transit observations of the active star WASP-52, hosting an inflated hot Jupiter, which presenta possible starspot occultation signal. By using this data set as a benchmark, we investigated whether the maskingof the transit profile distortion or modeling it with both a starspot model and a Gaussian process affects the shape ofthe transmission spectrum. Different methods produced spectra with the same shape and a robust detection of watervapor, and with 1σ different reference radii for the planet. The solutions of all methods are in agreement andreached a similar level of precision. Our WFC3 light curve of WASP-52b hints that starspot crossings mightbecome more problematic with JWSTʼs higher sensitivity and complete coverage of the transit profile.
关键词：planets and satellites: atmospheres;planets and satellites: gaseous planets;planets and satellites: individual (WASP-52b);stars: starspots;techniques: photometric;techniques: spectroscopic Supporting material: data behind figure
