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.

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

References in corpus (1)

• The Confined X-class Flares of Solar Active Region 2192

Cited by in corpus (13)

• Flare-productive active regions
• Extreme solar events
• A stellar flare-coronal mass ejection event revealed by X-ray plasma motions
• 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