Null transit detections of 68 radial velocity exoplanets observed by TESS

TL;DR

This study used TESS data to search for transits of 68 RV-detected exoplanets, finding no new transits and confirming the non-transiting nature of most, which helps refine their physical characteristics.

Contribution

First systematic search for transits of RV-detected exoplanets with TESS, providing constraints on their sizes and transit probabilities.

Findings

No new transits detected among 68 planets.

Excluded planets larger than 2.4 Earth radii assuming central transits.

Confirmed two known transiting planets in the sample.

Abstract

In recent years the number of exoplanets has grown considerably. The most successful techniques in these detections are the radial velocity (RV) and planetary transits techniques, the latter significantly advanced by the Kepler, K2 and, more recently, the TESS missions. The detection of exoplanets both by means of transit and by RVs is of importance, because this would allows characterizing their bulk densities, and internal compositions. The Transiting Exoplanet Survey Satellite (TESS) survey offers a unique possibility to search for transits of extrasolar planets detected by RV. In this work, we present the results of the search for transits of planets detected with the radial velocity technique, using the photometry of the TESS space mission. We focus on systems with super-Earths and Neptunes planets on orbits with periods shorter than 30 days. This cut is intended to keep objects with a relatively high transit probability, and is also consistent with duration of TESS observations on a single sector. Given the summed geometric transit probabilities, the expected number of transiting planets is $3.4 \pm 1.8$. The sample contains two known transiting planets. We report null results for the remaining 66 out of 68 planets studied, and we exclude in all cases planets larger than 2.4 R$_{\oplus}$, under the assumption of central transits. The remaining two planets orbit HD~136352 and have been recently been announced.