A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) -- III. Exploring the properties of young associations through their variables, dippers, and candidate exoplanets

TL;DR

This study uses high-precision light curves from the TESS mission to analyze young stellar associations, identifying variables, circumstellar disk properties, and candidate exoplanets, revealing a potentially higher frequency of giant planets in young systems.

Contribution

The paper presents a novel analysis of young associations using PATHOS tools to extract high-quality light curves and identify exoplanets and variables, providing new insights into early stellar and planetary evolution.

Findings

Identified 6 strong candidate exoplanets in young associations.

Estimated the ages of associations to be between 2 and 10 million years.

Suggested a higher occurrence rate of giant planets in young systems compared to field stars.

Abstract

Young associations in star forming regions are stellar systems that allow us to understand the mechanisms that characterise the stars in their early life and what happens around them. In particular, the analysis of the disks and of the exoplanets around young stars allows us to know the key processes that prevail in their evolution and understand the properties of the exoplanets orbiting older stars. The TESS mission is giving us the opportunity to extract and analyse the light curves of association members with high accuracy, but the crowding that affects these regions makes difficult the light curve extraction. In the PATHOS project, cutting-edge tools are used to extract high-precision light curves and identify variable stars and transiting exoplanets in open clusters and associations. In this work, I analysed the light curves of stars in five young ($\lesssim 10$ Myr) associations, searching for variables and candidate exoplanets. By using the rotational periods of the association members, I constrained the ages of the five stellar systems ($\sim 2$-$10$ Myr). I searched for dippers and I investigated the properties of the dust that forms the circumstellar disks. Finally, I searched for transiting signals, finding 6 strong candidate exoplanets. No candidates with radius $R_{\rm P}\lesssim 0.9 R_J$ have been detected, in agreement with the expectations. The frequency of giant planets resulted to be $\sim$2-3 %, higher than that expected for field stars ($\lesssim 1$ %); the low statistic makes this conclusion not strong, and new investigations on young objects are mandatory to confirm this result.