A Population of Dipper Stars from the Transiting Exoplanet Survey Satellite Mission

TL;DR

This paper reports the discovery and characterization of the largest sample of dipper stars, young stellar objects with dimming variability, using TESS data, revealing their properties and potential for future studies.

Contribution

The study presents a catalog of 414 variable stars including 293 dipper stars, expanding the known population and providing insights into their ages and disk presence.

Findings

Largest collection of dipper stars to date (293 confirmed plus 234 candidates)

Dipper stars are typically younger than 5 Myr, peaking at around 2 Myr

Most dipper stars exhibit infrared excess indicating circumstellar disks

Abstract

Dipper stars are a classification of young stellar objects that exhibit dimming variability in their light curves, dropping in brightness by 10-50%, likely induced by occultations due to circumstellar disk material. This variability can be periodic, quasi-periodic, or aperiodic. Dipper stars have been discovered in young stellar associations via ground-based and space-based photometric surveys. We present the detection and characterization of the largest collection of dipper stars to date: 293 dipper stars, including 234 new dipper candidates. We have produced a catalog of these targets, which also includes young stellar variables that exhibit predominately bursting-like variability and symmetric variability (equal parts bursting and dipping). The total number of catalog sources is 414. These variable sources were found in a visual survey of TESS light curves, where dipping-like variability was observed. We found a typical age among our dipper sources of <5 Myr, with the age distribution peaking at ~2 Myr, and a tail of the distribution extending to ages older than 20 Myr. Regardless of the age, our dipper candidates tend to exhibit infrared excess, which is indicative of the presence of disks. TESS is now observing the ecliptic plane, which is rich in young stellar associations, so we anticipate many more discoveries in the TESS dataset. A larger sample of dipper stars would enhance the census statistics of light curve morphologies and dipper ages.