日本地球惑星科学連合2019年大会

講演情報

[J] ポスター発表

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-EM19] 太陽物理学の最前線

2019年5月26日(日) 13:45 〜 15:15 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:今田 晋亮(名古屋大学宇宙地球環境研究所)、横山 央明(東京大学大学院理学系研究科)、清水 敏文(宇宙航空研究開発機構宇宙科学研究所)、勝川 行雄(自然科学研究機構国立天文台)

[PEM19-P05] Stellar flare of a close binary system monitored by the Hisaki satellite during the NICER-Hisaki Observing Campaign 2018-2019

*木村 智樹1岩切 渉2山崎 敦3村上 豪3土屋 史紀4吉岡 和夫5鳥海 森6北 元3桑原 正輝3 (1.東北大学学際科学フロンティア研究所、2.中央大学理工学部、3.JAXA宇宙科学研究所、4.東北大学惑星プラズマ大気研究センター、5.東京大学新領域創成科学研究科、6.国立天文台)

キーワード:恒星フレア、ひさき

Dynamics of stellar flare is still not well understood compared to that of the sun because of lack of continuous monitoring of distant stars in multiple wavelengths. Here we present a flare event at a close binary system, UX Arietis, monitored with the planetary extreme ultraviolet (EUV) space telescope Hisaki during the coordinated observing campaign with the NICER X-ray Telescope from late 2018 to early 2019. Time variability in the EUV spectrum of the binary was successfully monitored from the begging to the end of flare. Emission power at the EUV wavelengths peaked at ~6x10^24 W, which is comparable with that measured in the previous X-ray observations by e.g., the Advanced Satellite for Cosmology and Astrophysics (ASCA) (Gudel et al., 1999). The EUV spectrum showed emission lines of carbon, nitrogen, oxygen, and silicon ions. Electron temperature and density, emission measure, and ion balance were reduced from the emission lines by EUV spectral diagnostics. Dynamics of the stellar flare will be discussed based on comparison of the reduced plasma parameters with the X-ray spectrum measured with NICER.