In the observed spectra of O viii (3 MK), Fe xvii (6 MK), Mg xii (10 MK), and Si xiv (16 MK) lines, these flare-induced upflows/downflows appear as significant Doppler shifts of several tens to 130 km s ⁻¹, and the upflow velocity generally increases with temperature. With time-resolved high-resolution spectroscopic observations from the Chandra X-ray Observatory, we detected noticeable coronal plasma flows during several stellar flares on a nearby dMe star EV Lac. Compared to their solar counterparts, our knowledge on the coronal plasma dynamics of stellar flares and their connection to coronal mass ejections remains very limited. Stellar flares are characterized by sudden enhancement of electromagnetic radiation from the atmospheres of stars. These values provide clues in the extrapolation of the solar case to higher activity levels in other stars, suggesting that CMEs could indeed be a major cause of mass and angular momentum loss. Further consideration of the maximum available magnetic energy in starspots leads us to quantify its mass as likely lying in the range $2\times 10^ erg. Different physically justified length scales were used that allowed us to estimate lower and upper limits of the possible CME characteristics.
We investigate the kinematic and energetic properties of the CME using the ice-cream cone model for its three-dimensional structure in combination with the observed profile of the hydrogen column density decline with time. The temporal decay of the absorption is consistent with absorption by a CME undergoing self-similar evolution with uniform expansion velocity. We explore the scenario of a Coronal Mass Ejection (CME) being the cause of the observed continuous X-ray absorption of the Augsuperflare on the eclipsing binary Algol (the Demon Star).
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