Evidence for Centrifugal Breakout around the Young M Dwarf TIC 234284556

Autor: Palumbo, Elsa K., Montet, Benjamin T., Feinstein, Adina D., Bouma, Luke G., Hartman, Joel D., Hillenbrand, Lynne A., Gully-Santiago, Michael A., Banks, Kirsten A.
Rok vydání: 2021
Předmět:
Druh dokumentu: Working Paper
DOI: 10.3847/1538-4357/ac38a5
Popis: 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-loss mechanism known as centrifugal breakout for which there has been limited empirical evidence. In this paper, we present data from TESS, LCO, ASAS-SN, 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 ($\sim$1-day timescale) disappearance of a previously stable ($\sim$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 clouds and centrifugal breakout model and disfavor alternate scenarios, we discuss the possibility of a coronal mass ejection (CME) 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.
Comment: 27 pages, 17 figures, accepted for publication in ApJ
Databáze: arXiv
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