日本地球惑星科学連合2023年大会

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[E] 口頭発表

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM14] Frontiers in solar physics

2023年5月23日(火) 10:45 〜 12:15 展示場特設会場 (2) (幕張メッセ国際展示場)

コンビーナ:鳥海 森(宇宙航空研究開発機構 宇宙科学研究所)、横山 央明(京都大学大学院理学研究科)、今田 晋亮(東京大学理学系研究科地球惑星科学専攻)、Sterling Alphonse(NASA/MSFC)、座長:今田 晋亮(東京大学理学系研究科地球惑星科学専攻)、Sterling Alphonse(NASA/MSFC)

11:07 〜 11:22

[PEM14-06] High-velocity and massive prominence eruption leading to a CME associated with a superflare on an active star

*井上 峻1前原 裕之2野津 湧太3行方 宏介2、本田 敏志4、浪崎 桂一1、野上 大作1柴田 一成5 (1.京都大学、2.国立天文台、3.コロラド大学、4.兵庫県立大学、5.同志社大学)


キーワード:恒星フレア、スーパーフレア、恒星質量噴出

Stellar CMEs have recently received much attention for their impacts on exoplanets and stellar evolution. Detecting prominence eruptions, the initial phase of CMEs, as the blue-shifted excess component of Balmer lines is a technique to capture stellar CMEs. However, most of stellar prominence eruptions identified thus far have been slow and less than the surface escape velocity. Therefore, whether these eruptions were developing into stellar CMEs remained unknown. RS CVn-type stars are magnetically active binary systems composed of K-type and G-type stars. They are good targets for observing large superflares and prominence eruptions. In this study, we conducted simultaneous optical photometric observations with Transiting Exoplanet Survey Satellite and optical spectroscopic observations with the 3.8m Seimei Telescope for the RS CVn-type star V1355 Orionis (Inoue et al. 2023, ApJ). We detected a superflare releasing 7.0 × 1035 erg. In the early stage of this flare, a blue-shifted excess component of Hα extending its velocity up to 760 − 1690 km s-1 was observed and thought to originate from prominence eruptions. The velocity greatly exceeds the escape velocity of this star (i.e., ∼ 350 km s-1), which provides important evidence that stellar prominence eruptions can develop into CMEs. Furthermore, we found that the prominence is very massive (9.5 × 1018 g < M < 1.4 × 1021 g). The mass of this prominence is the largest ever observed. We confirmed that the scaling laws between the mass and kinetic energy of prominence and the energy of flares (Takahashi et al. 2016, ApJL; Namekata et al. 2022a, Nature Astronomy) hold for this event. This suggests that this very large prominence eruption and solar prominence eruptions may have a common physical mechanism. The high-velocity and massive prominence eruption detected in this study is a good sample to know how large an eruption the physical mechanism of solar prominence eruptions can cause at most.