Evidence for Centrifugal Breakout around the Young M Dwarf TIC 234284556

Magnetospheric clouds have been proposed as explanations for depth-varying dips in the phased light curves of young, magnetically active stars such as sigma Ori E and RIK-210. However, the stellar theory that first predicted magnetospheric clouds also anticipated an associated mass-balancing mechanism known as centrifugal breakout for which there has been limited empirical evidence. In this paper, we present data from the Transiting Exoplanet Survey Satellite, Las Cumbres Observatory, All-Sky Automated Survey for Supernovae, and Veloce on the 45 Myr M3.5 star TIC 234284556, and propose that it is a candidate for the direct detection of centrifugal breakout. In assessing this hypothesis, we examine the sudden (similar to 1 day timescale) disappearance of a previously stable (similar to 1 month timescale) transit-like event. We also interpret the presence of an anomalous brightening event that precedes the disappearance of the signal, analyze rotational amplitudes and optical flaring as a proxy for magnetic activity, and estimate the mass of gas and dust present immediately prior to the potential breakout event. After demonstrating that our spectral and photometric data support a magnetospheric cloud and centrifugal breakout model and disfavor alternate scenarios, we discuss the possibility of a coronal mass ejection or stellar wind origin of the corotating material and we introduce a reionization mechanism as a potential explanation for more gradual variations in eclipse parameters. Finally, after comparing TIC 234284556 with previously identified flux-dip stars, we argue that TIC 234284556 may be an archetypal representative of a whole class of young, magnetically active stars.

Automated summary

In this paper, the authors present data from various sources to propose TIC 234284556 as a candidate for the direct detection of centrifugal breakout. By analyzing the sudden disappearance of a stable transit-like event and the presence of an anomalous brightening event, they provide evidence supporting the magnetospheric cloud and centrifugal breakout model. They also discuss the possible origins of corotating material and offer a potential explanation for gradual variations in eclipse parameters.