Verification of eruptive mass loss scenario in red supergiants

• Project/Area Number: 16K05306
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Astronomy
• Research Institution: National Astronomical Observatory of Japan
• Principal Investigator: Asaki Yoshiharu 国立天文台, チリ観測所, 准教授 (00332148)
• Co-Investigator(Kenkyū-buntansha): 中川 亜紀治 鹿児島大学, 理工学域理学系, 助教 (60535631)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2016: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
• Keywords: 赤色超巨星 / 質量放出 / 恒星光球面撮像 / サブミリ波干渉計 / ALMA望遠鏡 / 高角度分解能観測 / 電波干渉計 / 質量損失 / サブミリ波 / 高角度分解能 / Red supergiant / Semi-regular variable / Evolved stars / Mass loss / Extreme OH/IR星 / ALMAサブミリ波高分解能観測 / 高空間分解能撮像観測 / 進化末期星メーザー / 宇宙物理 / 電波天文学 / 宇宙科学

Outline of Final Research Achievements

A red supergiant (RSG) is in the final stage of a stellar evolution for a heavier star than eight solar mass. In this stage, stellar nucleosynthesis materials are largely ejected from its photosphere. The materials may gravitationally be bounded later in a galaxy to form new stars possibly with earth-like planets and life. RSG's mass ejection, in other words, mass loss, is considered to be a very important process for a chemical evolution in the universe. In the corse of this research of RSGs' mass loss process, we have achieved the highest angular resolution of ALMA, one of the greatest telescopes in the world, to observe one of the most famous RSGs VY CMa whose distance is 3600 light years. We successfully captured the photosphere in a sub-millimeter wave region as well as the gas and dust anisotropically ejected from the RSG.

Academic Significance and Societal Importance of the Research Achievements

赤色超巨星の質量放出は、中小質量星の進化末期段階である漸近巨星分岐星（AGB）の延長線上で議論されることが多く、その質量とサイズがAGB星とは桁で異なるため3次元流体力学シミュレーションすらも難しい現象であり、その理解はAGB星と比較して相対的に不足している。RSGにはAGB星とは明らかに異なる「間欠的な質量放出」の特徴が潜むことがこれまで見過ごされており、本研究成果はRSGの質量放出機構を大きく見直す機会となる。また、本研究の過程において行ったALMAのサブミリ波最高角度分解能性能実証により2021年からの一般観測でその性能が利用可能となり、サブミリ波天体物理研究への波及効果は極めて大きい。

Research Products

• [Int'l Joint Research] KASI(韓国)
• [Int'l Joint Research] Leiden University(オランダ)
• [Int'l Joint Research] Ural Federal University(ロシア連邦)
• [Int'l Joint Research] The University of Western Australia(オーストラリア)
• [Int'l Joint Research] KASI(韓国)
• [Int'l Joint Research] ICRAR(オーストラリア)
• [Int'l Joint Research] Ural Federal University(ロシア連邦)
• [Int'l Joint Research] IGN(Spain)
• [Int'l Joint Research] JIVE(Netherlands)
• [Int'l Joint Research]
• [Journal Article] ALMA High-frequency Long Baseline Campaign in 2017: Band-to-band Phase Referencing in Submillimeter Waves (2020)
  • Author(s): Yoshiharu Asaki, Luke T. Maud, Edward B. Fomalont, Neil M. Phillips Neil, Akihiko Hirota, Tsuyoshi Sawada, Loreto Barcos-Mun~oz, Anita M. S. Richards, William R. F. Dent, Satoko Takahashi, Stuartt Corder, John M. Carpenter, Eric Villard, Elizabeth M. Humphreys
  • Journal Title: The Astrophysical Journal Supplement Series Volume: 247 Issue: 1 Pages: 23-23
  • DOI: 10.3847/1538-4365/ab6b20
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Astrometric VLBI Observations of the Galactic LPVs, Miras, and OH/IR stars (2018)
  • Author(s): Akiharu Nakagawa, Tomoharu Kurayama, Gabor Orosz, Ross A. Burns, Tomoaki Oyama, Takumi Nagayama, Takashi Miyata, Mamoru Sekido, Junichi Baba, keiichi Wada
  • Journal Title: Astrophysical Masers: Unlocking the Mysteries of the Universe, Proceedings of the International Astronomical Union, IAU Symposium Volume: 13 Issue: S336 Pages: 365-368
  • DOI: 10.1017/s1743921317009449
  • Open Access / Int'l Joint Research
• [Journal Article] Astrometry of OH/IR Stars Using 1612 MHz Hydroxyl Masers. I. Annual Parallaxes of WX Psc and OH138.0+7.2 (2017)
  • Author(s): Orosz, G.; Imai, H.; Dodson, R.; Rioja, M. J.; Frey, S.; Burns, R. A.; Etoka, S.; Nakagawa, A.; Nakanishi, H.; Asaki, Y.; Goldman, S. R.; Tafoya, D.
  • Journal Title: The Astronomical Journal Volume: 153 Issue: 3 Pages: 1-13
  • DOI: 10.3847/1538-3881/153/3/119
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] ALMA long baseline phase calibration using phase referencing (2016)
  • Author(s): Yoshiharu Asaki, Satoki Matsushita, Edward B. Fomalont, Stuartt A. Corder, Lars-Ake Nyman, William R. F. Dent, Neil M. Philips, Akihiko Hirota, Satoko Takahashi, Baltasar Vila-Vilaro, Bojan Nikolic, Todd R. Hunter, Anthony Remijan, Catherine Vlahakis
  • Journal Title: Proc. SPIE 9906, Ground-based and Airborne Telescopes VI Volume: 99065U Pages: 1-18
  • DOI: 10.1117/12.2232301
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] ALMA: fringe phase calibration (4): high frequency long baseline capability (2020)
  • Author(s): Y. Asaki, L. T. Maud, E. B. Fomalont, N. M. Phillips, A. Hirota, T. Sawada, L. Barcos-Mun~oz, A. M. S. Richards, W. R. F. Dent, S. Takahashi, S. Corder, J. Carpenter, E. Villard, E. M. Humphreys, H. Nagai, T. Tsukui
  • Organizer: 日本天文学会春季年会
• [Presentation] 長い周期を持つOH/IR星のVERAを用いた位置天文観測 (2019)
  • Author(s): 中川亜紀治, 倉山智春, 守田篤史, 加世田大地, 湯田晶斗, 松野雅子, 濱田翔太, 田中理央, 国立天文台VERAプロジェクト
  • Organizer: 日本天文学会
• [Presentation] 長周期変光星におけるVLBIとGaiaによる年周視差の比較 (2018)
  • Author(s): 中川亜紀治, 須藤広志, 倉山智春, 国立天文台VERAプロジェクト
  • Organizer: 日本天文学会
• [Presentation] VERAによるSiOメーザーを用いた周期の長いOH/IR星の位置天文VLBI観測 (2018)
  • Author(s): 中川亜紀治
  • Organizer: 日本天文学会2018年春季年会
• [Presentation] ALMA High Frequency (Long Baseline) Capability Commissioning Campaign 2017 (2017)
  • Author(s): Yoshiharu Asaki, Stuartt Corder, Satoko Takahashi, Ed Fomalont, William Dent, Luke Maud, Loreto Barcos
  • Organizer: Black Hole Astrophysics with VLBI
  • Place of Presentation: National Astronomical Observatory of Japan, Mitaka, Tokyo, Japan
  • Year and Date: 2017-03-27
  • Int'l Joint Research
• [Presentation] Intermittent Mass Blowout of the Red Supergiant S Per (2017)
  • Author(s): Yoshiharu Asaki
  • Organizer: IAU Symposia 336: Astrophysical Masers: Unlocking the Mysteries of the Universe
  • Int'l Joint Research
• [Presentation] Millimeter/submillimeter interferometry phase calibration strategy (2017)
  • Author(s): Yoshiharu Asaki
  • Organizer: ALMA Long Baseline Workshop
  • Int'l Joint Research / Invited
• [Presentation] Astrometric VLBI observation of the Galactic LPVs; Miras and OH/IR stars (2017)
  • Author(s): Akiharu Nakagawa
  • Organizer: IAU Symposia 336: Astrophysical Masers: Unlocking the Mysteries of the Universe
  • Int'l Joint Research
• [Presentation] OH/IR星を対象としたVLBI位置天文に基づく銀河動力学の観測的研究 (2017)
  • Author(s): 中川亜紀治
  • Organizer: 日本天文学会2017年秋季年会
• [Presentation] VERAによるOH/IR星のSiOメーザー位置天文観測 (2017)
  • Author(s): 中川亜紀治
  • Organizer: VLBI懇談会シンポジウム
• [Presentation] Intermittent Mass Blowout of the Red Supergiant S Per (2016)
  • Author(s): Y. Asaki, R. Burns, J. O. Chibueze, S-H. Cho, Y. K. Choi, R. Dodson, M. D. Gray, H. Imai, T-H. Jung, J. Kim, N. Matsumoto, R. Micheletto, C. Min, A. Nakagawa, K. Obara, G. Orosz, M. Oyadomari, M. J. Rioja, A. Sobolev, F. Watari, Y. Yun
  • Organizer: Pulsation 2016
  • Place of Presentation: Cumbress Spa, San Pedro de Atacama, Chile
  • Year and Date: 2016-11-28
  • Int'l Joint Research
• [Presentation] 赤色超巨星 S Perの間欠的質量放出 (2016)
  • Author(s): 朝木義晴
  • Organizer: 連星系・変光星・低温度星研究会
  • Place of Presentation: 神奈川県横浜市港北区日吉 慶應義塾大学日吉キャンパス
  • Year and Date: 2016-10-29
• [Presentation] Astrometry of the Galactic Miras and LPVs with a Japanese VLBI array "VERA" (2016)
  • Author(s): Akiharu Nakagawa, Tomoharu Kurayama, Gabor Orosz, VERA Project
  • Organizer: 13th European VLBI Network Symposium
  • Place of Presentation: St. Petersburg Scientific Center, Saint Petersburg, Russia
  • Year and Date: 2016-09-20
  • Int'l Joint Research
• [Presentation] Map Comparison between Quadruple Masers of the Red Supergiant S Per Using VLBI Source/Frequency Phase Transfer Technique (2016)
  • Author(s): Y. Asaki, R. Burns, J. O. Chibueze, S-H. Cho, Y. K. Choi, R. Dodson, M. D. Gray, H. Imai, T-H. Jung, J. Kim, N. Matsumoto, R. Micheletto, C. Min, A. Nakagawa, K. Obara, G. Orosz, M. Oyadomari, M. J. Rioja, A. Sobolev, F. Watari, Y. Yun
  • Organizer: Cool Stars 19th
  • Place of Presentation: Uppsala Konsert and Kongress, Uppsala, Sweden
  • Year and Date: 2016-06-06
  • Int'l Joint Research