A search for young exoplanets in Sectors 1-5 of the TESS full-frame images

Abstract

Young (<1Gyr) exoplanets represent a critically important area of exoplanet research, as they offer the opportunity to learn about the formation and early dynamic history of exoplanetary systems. However, finding young exoplanets is significantly complicated by the fast rotation and complex activity of their young host stars, which are often not well handled by stateof-the-art automatic pipelines. This work presents an alternative LOWESS-based pipeline focused specifically on detrending young stellar light curves from the 30-min cadence fullframe images produced by the Transiting Exoplanet Survey Satellite (TESS), and includes improvements such as automatic peak cutting of stellar variability and interpolation over masked transits to improve periodogram visibility and returned transit shapes. This work presents the details of the developed pipeline, along with initial results from its application to young stars within stellar associations in Sectors 1-5 of the TESS data. While no new exoplanet candidate signals were found in this work, interesting results included the recovery of all known 2-min TOIs around young stars in Sectors 1-5 from 30-min data alone, the recovery of the young exoplanet DS Tuc Ab, a number of young eclipsing binaries and a wide array of interesting rotation. A sensitivity analysis was also undertaken for each star, showing how the recovery of injected planets varied with both depth and period for each individual target. Challenges for future searches for young exoplanets are discussed, the largest being stellar rotation with periods less than 1 d and a lack of a large sample of confirmed young stars.