Towards an understanding of YSO variability: A multi-wavelength analysis of bursting, dipping, and symmetrically varying light curves of disc-bearing YSOs

TL;DR

This study analyzes multi-wavelength light curves of disc-bearing young stars to understand their variability patterns, revealing differences in amplitude, chromaticity, and inclination-based behaviors.

Contribution

It presents the first multi-wavelength structure function analysis of YSOs and proposes a model linking variability types to system inclination.

Findings

Dippers exhibit larger variability amplitudes than bursters and symmetric variables.

Bursters show less chromatic variability across all timescales.

Variability types correlate with system inclination angles.

Abstract

Using simultaneous optical and infrared light curves of disc-bearing young stars in NGC 2264, we perform the first multi-wavelength structure function study of YSOs. We find that dippers have larger variability amplitudes than bursters and symmetric variables at all timescales longer than a few hours. By analysing optical-infrared colour time-series, we also find that the variability in the bursters is systematically less chromatic at all timescales than the other variability types. We propose a model of YSO variability in which symmetric, bursting, and dipping behaviour is observed in systems viewed at low, intermediate, and high inclinations, respectively. We argue that the relatively short thermal timescale for the disc can explain the fact that the infrared light curves for bursters are more symmetric than their optical counterparts.