The Identification of 93 Day Periodic Photometric Variability for YSO YLW 16A

TL;DR

This study reports a 93-day periodic photometric variability in the young stellar object YLW 16A, suggesting a triple system with an eclipsing binary and a tertiary companion, providing insights into stellar evolution and disk dynamics.

Contribution

It presents the discovery of a 93-day periodicity in YLW 16A and proposes a triple-system model with a warped circum-binary disk, advancing understanding of YSO variability.

Findings

Discovered 92.6-day periodic variability in YLW 16A.

Proposed a triple-system model with an inner binary and tertiary companion.

Identified a possible circum-binary disk warp caused by the tertiary.

Abstract

Periodic variability in young stellar objects (YSOs) offers indirect evidence for an active dynamical mechanism. Starspots, accretion, stellar companions, and disk veiling can contribute to the photometric variability of YSOs. As part of an ongoing study of the Rho Oph star forming region, we report the discovery of 92.6 day periodic variations for the Class I YSO YLW 16A, observed over a period of three years. A SED model was fit to available photometric data for the object. We propose a triple-system with an inner binary with a period of 93 days eclipsed by a warped circum-binary disk. The nature of the secondary is unconstrained and could be stellar or sub-stellar. We report the discovery of a tertiary companion at a projected separation of ~40 AU that could account for the circum-binary disk warp. This light curve and model is similar to the model we proposed for WL 4 in previous work. Understanding these systems may lead to insights about the nature of stellar evolution and planetary formation, and provide valuable benchmarks for future theoretical modeling and near- and mid-infrared synoptic surveys of YSOs.