Stellar flares and the dark energy of CMEs

Abstract

Flares we observe on stars in white light, UV or soft X-rays are probably harbingers of coronal mass ejections (CMEs). If we use the Sun as a guide, large stellar flares will dissipate two orders of magnitude less X-ray radiative energy than the kinetic energy in the associated CME. Since coronal emission on active stars appears to be dominated by flare activity, CMEs pose a quandary for understanding the fraction of their energy budget stars can spend on magnetic activity. One answer is magnetic suppression of CMEs, in which the strong large-scale fields of active stars entrap and prevent CMEs unless their free energy exceeds a critical value. The CME-less flaring active region NOAA 2192 presents a possible solar analogue of this. Monster CMEs will still exist, and have the potential to ravage planetary atmospheres.

arXiv comment6 pages, to appear in Proceedings of IAU Symposium No. 320

References in corpus (9)

• The stellar activity-rotation relationship and the evolution of stellar dynamos
• Alfven Wave Solar Model (AWSoM): Coronal Heating
• EUV Flare Activity in Late-Type Stars
• The Confined X-class Flares of Solar Active Region 2192
• Implications of mass and energy loss due to coronal mass ejections on magnetically-active stars
• Our Sun. V. A Bright Young Sun Consistent with Helioseismology and Warm Temperatures on Ancient Earth and Mars
• A Global Wave-Driven MHD Solar Model with a Unified Treatment of Open and Closed Magnetic Field Topologies
• Flare Heating in Stellar Coronae
• X-ray Flares of EV Lac: Statistics, Spectra, Diagnostics

Cited by in corpus (15)

• Flare-productive active regions
• Extreme solar events
• A stellar flare-coronal mass ejection event revealed by X-ray plasma motions
• Mass Loss Rates from Coronal Mass Ejections: A Predictive Theoretical Model for Solar-Type Stars
• A census of Coronal Mass Ejections on solar-like stars
• Detection of Flare-induced Plasma Flows in the Corona of EV Lac with X-ray Spectroscopy
• Stellar Coronal Mass Ejections
• Stellar coronal mass ejections II. Constraints from spectroscopic observations
• Torus-Stable Zone Above Starspots
• Properties of quasi-periodic pulsations in solar flares from a single active region
• The Flare-Activity of 2MASSJ16111534-1757214 in the Upper Scorpius association
• Doppler-shifted Signatures in the Chromospheric Line Profiles of II Pegasi
• Investigating Possible Stellar Coronal Mass Ejections in M-type Dwarfs Using the CARMENES DR1 Spectra
• A Possible Stellar CME Event Associated with a Long-duration Optical Flare on the RS CVn-type Star UX Arietis
• (Simulating) Coronal Mass Ejections in Active Stars