The physical environment when stellar hyper flares occur

• Project/Area Number: 17K05392
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Astronomy
• Research Institution: Chuo University
• Principal Investigator: Tsuboi Yohko 中央大学, 理工学部, 教授 (70349223)
• Project Period (FY): 2017-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: フレア / X線天文 / 可視光観測 / X線 / 偏光 / 可視光 / モニター / 星

Outline of Final Research Achievements

(1) We searched for super flares, which occur extremely infrequently, using the MAXI all-sky X-ray monitor, and made follow-up observations at various wavelengths. As a result, we obtained several correlations of physical quantities over many orders of magnitude, and statistically constrained the volume, shape, and loop length of the plasma loop almost for the first time. (2) We confirmed the existence of a proto-brown dwarf or a protostar with a very low mass and a age as young as about 1,000 yr, by multi-wavelength observations, and provided constraints on the age and mass at which the star begins to emit X-rays. (3) We made an optical system with high sensitivity to polarization, which provides information on the geometry and position of flare loops, using CFRP and thin Si crystals. Then we confirmed extremely high spectral resolution and polarization sensitivity.

Academic Significance and Societal Importance of the Research Achievements

人類の文化的生活を脅かすような巨大なフレアが我々の太陽で起こるか否かは切実な問題である。本研究では、ハイパーフレアとも呼ぶべき、太陽フレアの最大規模に比べても６桁も大きいフレアのサーチを全天に対して行い、その発生機構についてさまざまな制限を与えた。ハイパーフレアにおけるフレアループの大きさを明らかにし、それが星自体の半径の１０倍以上にもなりえることや、その断面積が星表面の巨大黒点と同程度であること、などである。これは逆に言えば、太陽では巨大な黒点が出現して初めて巨大フレアが起こるであろうことを示唆する。またフレアの幾何を明らかにするX線偏光計の優れた性能を実測し、実現化を進めた。

Research Products

• [Int'l Joint Research] NASA(米国)
• [Int'l Joint Research] NASA(米国)
• [Journal Article] X-ray/Hα scaling relationships in stellar flares (2022)
  • Author(s): Kawai Hiroki、Tsuboi Yohko、Iwakiri Wataru B、Maeda Yoshitomo、Katsuda Satoru、Sasaki Ryo、Kohara Junya、MAXI TEAM
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 74 Issue: 2 Pages: 477-487
  • DOI: 10.1093/pasj/psac008
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Detailed design of the science operations for the XRISM mission (2021)
  • Author(s): Terada Yukikatsu、Holland Matt、Loewenstein Michael、Tashiro Makoto、他35名（35番目）
  • Journal Title: Journal of Astronomical Telescopes, Instruments, and Systems Volume: 7 Issue: 03 Pages: 037001-037001
  • DOI: 10.1117/1.jatis.7.3.037001
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The RS CVn-type Star GT Mus Shows Most Energetic X-Ray Flares Throughout the 2010s (2021)
  • Author(s): Sasaki, Ryo et al.
  • Journal Title: The Astrophysical Journal Letters Volume: 910 Issue: 1 Pages: 1-13
  • DOI: 10.3847/1538-4357/abde38
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Optical and X-ray observations of stellar flares on an active M dwarf AD Leonis with the Seimei Telescope, SCAT, NICER, and OISTER (2020)
  • Author(s): Namekata, Kosuke et al.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 72 Issue: 4 Pages: 4-15
  • DOI: 10.1093/pasj/psaa051
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Inverse First Ionization Potential Effects in Giant Solar Flares Found from Earth X-Ray Albedo with Suzaku/XIS (2020)
  • Author(s): Katsuda Satoru et al.
  • Journal Title: The Astrophysical Journal Volume: 891 Issue: 2 Pages: 126-126
  • DOI: 10.3847/1538-4357/ab7207
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Detection of polarized gamma-ray emission from the Crab nebula with the Hitomi Soft Gamma-ray Detector (2018)
  • Author(s): Hitomi collaboration
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 6 Pages: 113-113
  • DOI: 10.1093/pasj/psy118
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The 7-year MAXI/GSC X-Ray Source Catalog in the High Galactic Latitude Sky (3MAXI) (2018)
  • Author(s): Kawamuro T., Ueda Y., Shidatsu M., Hori T., Morii M., Nakahira S., Isobe N., Kawai N., Mihara T., Matsuoka M., Morita T., Nakajima M., Negoro H., Oda S., Sakamoto T., Serino M., Sugizaki M., Tanimoto A., Tomida H., Tsuboi, Y. 他 11 名
  • Journal Title: The Astrophysical Journal Supplement Series Volume: 238 Issue: 2 Pages: 32-32
  • DOI: 10.3847/1538-4365/aad1ef
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Extremely Dense Cores Associated with Chandra Sources in Ophiuchus A: Forming Brown Dwarfs Unveiled? (2018)
  • Author(s): Kawabe Ryohei、Hara Chihomi、Nakamura Fumitaka,...,Oasa Yumiko et al.
  • Journal Title: The Astrophysical Journal Volume: 866 Issue: 2 Pages: 141-155
  • DOI: 10.3847/1538-4357/aae153
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Hitomi X-ray observation of the pulsar wind nebula G21.5-0.9 (2018)
  • Author(s): Hitomi Collaboration、Aharonian Felix、...、Kohmura Takayoshi...、et al (他191名）
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 3 Pages: 1-16
  • DOI: 10.1093/pasj/psy027
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Hitomi (ASTRO-H) X-ray Astronomy Satellite (2018)
  • Author(s): Tadayuki Takahashi, Yuto Ichinohe (73/270) et al.
  • Journal Title: Journal of Astronomical Telescopes, Instruments, and Systems Volume: 4 Issue: 02 Pages: 021402-021402
  • DOI: 10.1117/1.jatis.4.2.021402
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Glimpse of the highly obscured HMXB IGR J16318-4848 with Hitomi (2018)
  • Author(s): Hitomi Collaboration, A. Bamba et al.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 2 Pages: 17-17
  • DOI: 10.1093/pasj/psx154
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Hitomi observations of the LMC SNR N 132D: Highly redshifted X-ray emission from iron ejecta (2018)
  • Author(s): Hitomi collaboration, A. Bamba, et al.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 2 Pages: 16-16
  • DOI: 10.1093/pasj/psx151
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Hitomi X-ray studies of giant radio pulses from the Crab pulsar (2018)
  • Author(s): Hitomi Collaboration, Aya Bamba, et al.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 2 Pages: 15-15
  • DOI: 10.1093/pasj/psx083
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for thermal X-ray features from the Crab nebula with the Hitomi soft X-ray spectrometer (2018)
  • Author(s): Hitomi Collaboration, Aya Bamba, et al.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 2 Pages: 14-14
  • DOI: 10.1093/pasj/psx072
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Hitomi observation of radio galaxy NGC1275: The first X-ray microcalorimeter spectroscopy of Fe-Kα line emission from an active galactic nucleus (2018)
  • Author(s): Hitomi Collaboration, Aya Bamba, et al.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 2 Pages: 13-13
  • DOI: 10.1093/pasj/psx147
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Atomic data and spectral modeling constraints from high-resolution X-ray observations of the Perseus cluster with Hitomi* (2018)
  • Author(s): Hitomi Collaboration, Aya Bamba
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 2 Pages: 12-12
  • DOI: 10.1093/pasj/psx156
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Temperature structure in the Perseus cluster core observed with Hitomi (2018)
  • Author(s): Hitomi Collaboration, Aya Bamba, et al.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 2 Pages: 11-11
  • DOI: 10.1093/pasj/psy004
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Measurements of resonant scattering in the Perseus Cluster core with Hitomi SXS (2018)
  • Author(s): Hitomi Collaboration, Aya Bamba, et al.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 2 Pages: 10-10
  • DOI: 10.1093/pasj/psx127
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Atmospheric gas dynamics in the Perseus cluster observed with Hitomi (2018)
  • Author(s): Hitomi Collaboration, Aya Bamba, et al.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 2 Pages: 9-9
  • DOI: 10.1093/pasj/psx138
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The 7-year MAXI/GSC Source Catalog of the Low-Galactic-latitude Sky (3MAXI) (2018)
  • Author(s): Hori T., Shidatsu, M., Ueda, Y., Kawamuro, T., Morii, M., Nakahira, S., Isobe, N., Kawai, N., Mihara T., Matsuoka, M., Morita, T., Nakajima, M., Negoro, H., Oda, S., Sakamoto, T., Serino, M., Sugizaki, M., Tanimoto, A., Tomida, H., Tsuboi, Y. 他 10 名
  • Journal Title: The Astrophysical Journal Supplement Series Volume: 235 Issue: 1 Pages: 7-7
  • DOI: 10.3847/1538-4365/aaa89c
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A Universal Correlation between the Duration and the X-ray Luminosity in Stellar Flares (2018)
  • Author(s): Yohko Tsuboi; Ryo Sasaki; Yasuharu Sugawara; Masaru Matsuoka
  • Journal Title: Acta Polytechnica CTU Proceedings Volume: 掲載決定済み
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Solar abundance ratios of the iron-peak elements in the Perseus cluster (2017)
  • Author(s): Aharonian, F., Bamba, A. et al.
  • Journal Title: Nature Volume: 551 Issue: 7681 Pages: 478-480
  • DOI: 10.1038/nature24301
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Multi-messenger Observations of a Binary Neutron Star Merger (2017)
  • Author(s): Abbott B. P., Abbott, R., Abbott, T. D., Acernese, F., Ackley, K., Adams, C., Adams, T., Addesso, P., Adhikari, R. X., Adya, V. B., Affeldt, C., Afrough, M., Agarwal, B., Agathos, M., Agatsuma, K., Aggarwal, N., Aguiar, O. D., Aiello, L., Ain, A., Ajith, P. 他 Negoro, H. 含む 3656 名
  • Journal Title: The Astrophysical Journal Letters Volume: 848 Issue: 2 Pages: 1-59
  • DOI: 10.3847/2041-8213/aa91c9
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Stellar wind measurements for Colliding Wind Binaries using X-ray observations (2017)
  • Author(s): Sugawara Yasuharu、Maeda Yoshitomo、Tsuboi Yohko
  • Journal Title: Proceedings of the International Astronomical Union Volume: 329 Issue: S329 Pages: 448-448
  • DOI: 10.1017/s1743921317003325
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] The X-ray monitoring of the long-period colliding wind binaries (2017)
  • Author(s): Sugawara Yasuharu、Maeda Yoshitomo、Tsuboi Yohko
  • Journal Title: The X-ray Universe 2017, Proceedings of the conference held 6-9 June, 2017 in Rome, Italy Volume: - Pages: 215-215
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A Correlation on Stellar Flares detected with MAXI - Quiescent Luminosity vs. Flare Energy - (2017)
  • Author(s): Ryo Sasaki; Yohko Tsuboi; Satoru Katsuda; Ken Yabuki; Yumiko Nakamura; Yasuharu Sugawara; Masaru Matsuoka; MAXI Team
  • Journal Title: The X-ray Universe 2017, Proceedings of the conference held 6-9 June, 2017 in Rome, Italy Volume: - Pages: 201-201
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] 巨大フレア同時観測で得た軟X線とHα線のフレア減衰時間の相関 (2021)
  • Author(s): 河合広樹, 坪井陽子, 岩切渉, 佐々木亮 (中央大学), 前田良知, 菅原泰晴 (JAXA/ISAS), 勝田哲 (埼玉 大学), 他 MAXI チーム
  • Organizer: 日本天文学会2021年秋季年会
• [Presentation] TESSで観測したけんびきょう座AT星のフレア検出方法およびフレア発生頻度分布について (2021)
  • Author(s): 岡本豊, 坪井陽子, 岩切渉, 佐々木亮, 河合広樹 (中央大学), 行方宏介 (国立天文台), 野津湧太 (コロラ ド大学/東京工業大学), 河合誠之 (東京工業大学), 河原創 (東京大学), 他 MAXI チーム
  • Organizer: 日本天文学会2021年秋季年会
• [Presentation] 多波長同時観測で迫るおひつじ座UX星で生じた巨大フレアの特徴 (2) (2021)
  • Author(s): 北古賀智紀, 坪井陽子, 岩切渉, 河合広樹, 佐々木亮 (中央大学), 米倉覚則 (茨城大学), 岳藤一宏 (JAXA), 新沼浩太郎, 元木業人, 藤沢健太, 青木貴弘 (山口大学), 下条圭美, 梅本智文 (NAOJ)
  • Organizer: 日本天文学会2022年春季年会
• [Presentation] 湾曲 Si 結晶を用いたブラッグ反射型偏光計の分光性能評価 (2) (2021)
  • Author(s): 井上諒大, 坪井陽子, 岩切渉, 中島七海 (中央大学), 前田良知 (宇宙科学研究所)
  • Organizer: 日本天文学会2022年春季年会
• [Presentation] 全天X線監視装置MAXIを用いた巨大恒星フレアの統計的研究 (2021)
  • Author(s): 佐々木亮 他
  • Organizer: 日本天文学会
• [Presentation] 多波長同時観測で迫るおひつじ座UX星で生じた巨大フレアの特徴 (2021)
  • Author(s): 北古賀智紀 他
  • Organizer: 日本天文学会
• [Presentation] 湾曲 Si 結晶を用いたブラッグ反射型偏光計の偏光性能評価(2) (2021)
  • Author(s): 芳野史弥 他
  • Organizer: 日本天文学会
• [Presentation] 超小型X線衛星NinjaSatに搭載する小型で軽量なX線コリメーターの開発 (2021)
  • Author(s): 岩切渉 他
  • Organizer: 日本天文学会
• [Presentation] 超低光度前主系列星 J162656.43-243301.5 周囲のtransition diskのALMA観測II (2021)
  • Author(s): 杉谷朱泉 他
  • Organizer: 日本天文学会
• [Presentation] TESSとMAXIを用いた恒星フレアにおける白色光フレアエネルギーとX線最大光度の関係 (2020)
  • Author(s): 岡本豊 他
  • Organizer: 日本天文学会
• [Presentation] 湾曲Si結晶を用いたブラッグ反射型偏光計の分光性能評価 (2020)
  • Author(s): 井上諒大 他
  • Organizer: 日本天文学会
• [Presentation] Athena衛星に搭載するSPO望遠鏡のDLCコーティング (2020)
  • Author(s): 芳野史弥 他
  • Organizer: 日本天文学会
• [Presentation] A Large X-ray Stellar Flare from the RS CVn type Star Sigma Gem Observed with MAXI and NICER (2020)
  • Author(s): Sasaki et al.
  • Organizer: American Astronomical Society meeting #235
  • Int'l Joint Research
• [Presentation] Identifying stellar flares from MAXI/GSC imaging data using Deep Learning methods (2020)
  • Author(s): Sato et al.
  • Organizer: American Astronomical Society meeting #235
  • Int'l Joint Research
• [Presentation] X-ray Emission from Stars ~The Results Obtained with MAXI~ (2019)
  • Author(s): Y. Tsuboi and R. Sasaki
  • Organizer: Multifrequency Behaviour of High Energy Cosmic Sources - XIII - MULTIF2019
  • Int'l Joint Research / Invited
• [Presentation] MAXI--NICER連携（MANGA）によるRS CVn型星GT Musの巨大フレア観測 (2019)
  • Author(s): 佐々木亮、坪井陽子、岩切渉、Keith Gendreau、Michael Corcoran、濱口 健二、Stephen Drake、Craig Markwardt、Zaven Arzoumanian、前田良知、河合広樹、佐藤樹、三原建弘, 中平聡、芹野素子、根來均、榎戸輝揚、志達めぐみ
  • Organizer: 日本天文学会2019年春季年会
• [Presentation] A Large X-ray Stellar Flare from the RS CVn type Star GT Mus Observed with MAXI and NICER (2018)
  • Author(s): Sasaki, Ryo; Tsuboi, Yohko; Iwakiri, Wataru; et al.
  • Organizer: American Astronomical Society, AAS Meeting #233
• [Presentation] X線、Hα線、電波による巨大恒星フレアの同時多波長観測体制の構築 (2018)
  • Author(s): 河合広樹、坪井陽子、米倉覚則、岳藤一宏、岩切渉、佐々木亮、梅本智文、新沼浩太郎、青木貴弘
  • Organizer: 日本天文学会2018年秋季年会
• [Presentation] 炭素繊維強化プラスチックを用いた湾曲結晶偏光計の鏡面精度の改良 (2018)
  • Author(s): 塚田晃大、 坪井陽子、 前田良知、 岩切渉、 佐々木亮、 黒川裕平
  • Organizer: 日本天文学会2018年秋季年会
• [Presentation] MAXI-NICER連携(MANGA)による巨大恒星フレアの軟X線観測 (2018)
  • Author(s): 岩切渉、佐々木亮、河合広樹、坪井陽子、Keith Gendreau、Zaven Arzoumanian、Stephen Drake、Michael Corcoran、濱口健二、三原建弘, 中平聡、芹野素子、根來均、榎戸輝揚
  • Organizer: 日本天文学会2018年秋季年会
• [Presentation] 放射層を持たない晩期 M 型星の自転と定常 X 線光度の関係 (2018)
  • Author(s): 佐藤樹、 坪井陽子、 岩切渉、 杉田龍斗、 佐々木亮
  • Organizer: 日本天文学会2018年秋季年会
• [Presentation] Swift/XMM-NewtonによるWolf-Rayet連星系WR 125のX線観測 (2018)
  • Author(s): 菅原泰晴, 前田良知, 坪井陽子
  • Organizer: 日本天文学会2018年春季年会
  • Invited
• [Presentation] XMM-Newton衛星で偶然検出された恒星フレアとその発生源 (2018)
  • Author(s): 中村優美子, 坪井陽子, 本田敏志, 勝田哲, 河合広樹(中 央大学), 菅原泰晴, 佐々木亮, 杉田龍斗
  • Organizer: 日本天文学会2018年春季年会
• [Presentation] A Universal Correlation between the Duration and the X-ray Luminosity in Stellar Flares (2017)
  • Author(s): Yohko Tsuboi; Ryo Sasaki; Yasuharu Sugawara; Masaru Matsuoka
  • Organizer: XII Multifrequency Behaviour of High Energy Cosmic Sources Workshop
  • Int'l Joint Research / Invited
• [Presentation] Giant Stellar Flares detected with MAXI (2017)
  • Author(s): Yohko Tsuboi; R. Sasaki; K. Yamazaki; Y. Nakamura; K. Yabuki; A. Kawagoe; S. Kaneto; Y. Sugawara; H. Negoro; the MAXI team
  • Organizer: The X-ray Universe 2017
  • Int'l Joint Research / Invited
• [Presentation] Giant Stellar Flares (2017)
  • Author(s): Yohko Tsuboi; R. Sasaki; Y. Sugawara; Y. Maeda; Y. Nakamura; K. Yabuki; A. Kawagoe; S. Kaneto; S. Katsuda; H. Negoro; the MAXI team
  • Organizer: Variable Galactic Gamma-Ray Sources 2017
  • Int'l Joint Research / Invited
• [Presentation] Astronomy Communications with Students using Metropolitan Telescopes (2017)
  • Author(s): Y. Tsuboi; R. Iizuka; H. Kawai
  • Organizer: COMMUNICATING ASTRONOMY WITH THE PUBLIC 2018 in Fukuoka
  • Int'l Joint Research
• [Presentation] A Correlation on Stellar Flares detected with MAXI - Quiescent Luminosity vs. Flare Energy - (2017)
  • Author(s): Ryo Sasaki; Yohko Tsuboi; Satoru Katsuda; Ken Yabuki; Yumiko Nakamura; Yasuharu Sugawara; Masaru Matsuoka; MAXI Team
  • Organizer: The X-ray Universe 2017
  • Int'l Joint Research / Invited
• [Presentation] A correlation on hyper X-ray stellar flares between the quiescent luminosity and the largest flare energy detected with MAXI (2017)
  • Author(s): Ryo Sasaki; Yohko Tsuboi; Satoru Katsuda; Ken Yabuki; Yumiko Nakamura; Yasuharu Sugawara; Masaru Matsuoka; MAXI Team
  • Organizer: Helicity Thinkshop 3
  • Int'l Joint Research / Invited
• [Presentation] Stellar wind measurements for Colliding Wind Binaries using X-ray observations (2017)
  • Author(s): Yasuharu Sugawara; Yoshitomo Maeda; Yohko Tsuboi
  • Organizer: the International Astronomical Union, IAU Symposium
  • Int'l Joint Research
• [Presentation] The Extended Linear Correlation between the Hα and the Soft X-ray Emissions in the Solar and Stellar Flares (2017)
  • Author(s): H. Kawai; Y. Tsuboi; R.Iizuka; S. Yamada; S. Katsuda; R. Sasaki; Y. Nakamura; R. Sugita; MAXI Team
  • Organizer: Helicity Thinkshop 3
• [Presentation] 全天X線監視装置MAXIを用いた星のフレアサーチシステムの開発 (2017)
  • Author(s): 塚田晃大, 坪井陽子, 佐々木亮, 勝田哲, 湯川千夏
  • Organizer: 日本天文学会2017年秋季年会
• [Presentation] 全天X線監視装置MAXIによって得られたdMe型星のフレア発生頻度分布 (2017)
  • Author(s): 佐々木亮, 坪井陽子, 勝田哲, 中村優美子, 松岡勝 他 MAXI チーム
  • Organizer: 日本天文学会2017年秋季年会
• [Presentation] 恒星フレアの軟X線とHα線放射領域の高度比 (2017)
  • Author(s): 河合広樹, 坪井陽子, 飯塚亮, 山田宗次郎, 勝田哲, 佐々木亮, 中村優美子, 杉田龍斗
  • Organizer: 日本天文学会2017年秋季年会
• [Presentation] 星のフレアの相関内に見られる微細構造 (2017)
  • Author(s): 坪井陽子, 兼藤聡一郎, 佐々木亮, 中村優美子, 菅原泰晴, MAXI チーム
  • Organizer: 日本天文学会2017年秋季年会
• [Presentation] 長周期Wolf-Rayet連星系WR 19のX線モニタリング観測 II (2017)
  • Author(s): 菅原泰晴, 前田良知, 坪井陽子
  • Organizer: 日本天文学会2017年秋季年会
• [Book] 「全天X線監視装置MAXIで捉えた恒星からの超巨大X線フレア」天文月報2020年10月号 (2019)
  • Author(s): 坪井陽子
  • Total Pages: 5
  • Publisher: 日本天文学会
• [Book] 「X線で見る恒星のコロナとフレア」プラズマ核融合学会誌12月号 (2019)
  • Author(s): 坪井陽子
  • Total Pages: 6
  • Publisher: プラズマ核融合学会