English

Evidence for Centrifugal Breakout around the Young M Dwarf TIC 234284556

Solar and Stellar Astrophysics 2022-02-02 v2

Abstract

Magnetospheric clouds have been proposed as explanations for depth-varying dips in the phased light curves of young, magnetically active stars such as σ\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 (\sim1-day timescale) disappearance of a previously stable (\sim1-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.

Keywords

Cite

@article{arxiv.2107.05649,
  title  = {Evidence for Centrifugal Breakout around the Young M Dwarf TIC 234284556},
  author = {Elsa K. Palumbo and Benjamin T. Montet and Adina D. Feinstein and Luke G. Bouma and Joel D. Hartman and Lynne A. Hillenbrand and Michael A. Gully-Santiago and Kirsten A. Banks},
  journal= {arXiv preprint arXiv:2107.05649},
  year   = {2022}
}

Comments

27 pages, 17 figures, accepted for publication in ApJ