arXiv subjects

Â. R. G. Santos

Publications and source records attributed to Â. R. G. Santos.

2 recordsLinked to original sources

arXiv2025

Non-transiting exoplanets as a means of understanding star-planet interactions in close-in systems

Previous studies showed evidence of a dearth of close-in exoplanets around fast rotators, which can be explained by the combined action of intense tidal and magnetic interactions between planets and their host star. Detecting more exoplanets experiencing such interactions, with orbits evolving on short timescales, is therefore crucial to improve our understanding of the underlying physical mechanisms. For this purpose, we performed a new search for close-in non-transiting substellar companions in the Kepler data, focusing on orbital periods below 2.3 days. We focused on main-sequence solar-type stars and subgiant stars for which a surface rotation period was measured. For each star, we looked for an excess in the power spectral density of the light curve, which could correspond to the signature of a close-in non-transiting companion. We compared our candidates with existing catalogues to eliminate potential contaminants in our sample, and we visually inspected the phase-folded light curve and its wavelet decomposition. We identify 88 stars exhibiting a signature consistent with the presence of a close non-transiting substellar companion. We show that the objects in our sample are located mostly within the dearth zone, emphasising the importance of performing follow-up of such systems in order to gather observational evidence of star-planet interactions.

astro-ph.EP↗

arXiv2025

Kepler meets Gaia DR3: homogeneous extinction-corrected color-magnitude diagram and binary classification

The original Kepler mission has delivered unprecedented high-quality photometry. These data have impacted numerous research fields (e.g., asteroseismology and exoplanets), and continue to be an astrophysical goldmine. Because of this, thorough investigations of the ~ 200,000 stars observed by Kepler remain of paramount importance. In this paper, we present a state-of-the-art characterization of the Kepler targets based on Gaia DR3 data. We place the stars on the color-magnitude diagram (CMD), account for the effects of interstellar extinction, and classify targets into several CMD categories (dwarfs, subgiants, red giants, photometric binaries, and others). Additionally, we report various categories of candidate binary systems spanning a range of detection methods, such as Renormalised Unit Weight Error (RUWE), radial velocity variables, Gaia non-single stars (NSS), Kepler and Gaia eclipsing binaries from the literature, among others. First and foremost, our work can assist in the selection of stellar and exoplanet host samples regarding CMD and binary populations. We further complement our catalog by quantifying the impact that astrometric differences between Gaia data releases have on CMD location, assessing the contamination in asteroseismic targets with properties at odds with Gaia, and identifying stars flagged as photometrically variable by Gaia. We make our catalog publicly available as a resource to the community when researching the stars observed by Kepler.

astro-ph.SR↗