[P-EM14] Frontiers in solar physics

[PEM14-05] Suppression of Torus Instability on the Sun and Other Cool Stars

★Invited Papers

*Xudong Sun¹、Tibor Torok²、Marc DeRosa³ (1.University of Hawai'i at Manoa、2.Predictive Science Inc.、3.Lockheed Martin Solar and Astrophysics Laboratory)

キーワード：Coronal mass ejection, Torus instability, Magnetic field

Despite the frequent detection of stellar super flares, reports on stellar coronal mass ejections (CMEs) are rare. This is in contrast with our Sun, where almost all large flares are accompanied by a CME. In this talk, I will review this so-called “missing stellar CME conundrum”. I will then use an analytical coronal magnetic field model to demonstrate that the torus instability, a leading mechanism for solar CMEs, tends to be suppressed in stellar magnetic environment. Contributing factors include larger starspots, stronger global dipole field, and more closed magnetic geometry compared to the Sun. Suppression of the torus instability may contribute to the low apparent CME rate on cool stars.