太陽系科学研究系

早川 雅彦

ハヤカワ マサヒコ  (Masahiko HAYAKAWA)

基本情報

所属
国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 太陽系科学研究系 助教
東京大学 大学院理学系研究科 地球惑星科学専攻 助教
学位
理学博士(名古屋大学)
理学修士(名古屋大学)

連絡先
hayakawaplaneta.sci.isas.jaxa.jp
J-GLOBAL ID
200901009402364446
researchmap会員ID
1000363026

論文

 62
  • Shota Kikuchi, Kei Shirai, Ko Ishibashi, Koji Wada, Yasuhiro Yokota, Rie Honda, Toshihiko Kadono, Yuri Shimaki, Naoya Sakatani, Kazunori Ogawa, Hirotaka Sawada, Takanao Saiki, Yuya Mimasu, Yuto Takei, Seiji Sugita, Toru Kouyama, Naru Hirata, Satoru Nakazawa, Makoto Yoshikawa, Satoshi Tanaka, Sei-ichiro Watanabe, Yuichi Tsuda, Masahiko Arakawa
    Advances in Space Research 2024年5月  
  • Moe Matsuoka, Ei-ichi Kagawa, Kana Amano, Tomoki Nakamura, Eri Tatsumi, Takahito Osawa, Takahiro Hiroi, Ralph Milliken, Deborah Domingue, Driss Takir, Rosario Brunetto, Antonella Barucci, Kohei Kitazato, Seiji Sugita, Yuri Fujioka, Osamu Sasaki, Shiho Kobayashi, Takahiro Iwata, Tomokatsu Morota, Yasuhiro Yokota, Toru Kouyama, Rie Honda, Shingo Kameda, Yuichiro Cho, Kazuo Yoshioka, Hirotaka Sawada, Masahiko Hayakawa, Naoya Sakatani, Manabu Yamada, Hidehiko Suzuki, Chikatoshi Honda, Kazunori Ogawa, Kei Shirai, Cateline Lantz, Stefano Rubino, Hisayoshi Yurimoto, Takaaki Noguchi, Ryuji Okazaki, Hikaru Yabuta, Hiroshi Naraoka, Kanako Sakamoto, Shogo Tachibana, Toru Yada, Masahiro Nishimura, Aiko Nakato, Akiko Miyazaki, Kasumi Yogata, Masanao Abe, Tatsuaki Okada, Tomohiro Usui, Makoto Yoshikawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Satoru Nakazawa, Sei-ichiro Watanabe, Yuichi Tsuda
    Communications Earth & Environment 4(1) 2023年9月27日  査読有り
    Abstract Returned samples from Cb-type asteroid (162173) Ryugu exhibit very dark spectra in visible and near-infrared ranges, generally consistent with the Hayabusa2 observations. A critical difference is that a structural water absorption of hydrous silicates is around twice as deep in the returned samples compared with those of Ryugu’s surface, suggesting Ryugu surface is more dehydrated. Here we use laboratory experiments data to indicate the spectral differences between returned samples and asteroid surface are best explained if Ryugu surface has (1) higher porosity, (2) larger particle size, and (3) more space-weathered condition, with the last being the most effective. On Ryugu, space weathering by micrometeoroid bombardments promoting dehydration seem to be more effective than that by solar-wind implantation. Extremely homogeneous spectra of the Ryugu’s global surface is in contrast with the heterogeneous S-type asteroid (25143) Itokawa’s spectra, which suggests space weathering has proceeded more rapidly on Cb-type asteroids than S-type asteroids.
  • Kohji Tsumura, Shuji Matsuura, Kei Sano, Takahiro Iwata, Hajime Yano, Kohei Kitazato, Kohji Takimoto, Manabu Yamada, Tomokatsu Morota, Toru Kouyama, Masahiko Hayakawa, Yasuhiro Yokota, Eri Tatsumi, Moe Matsuoka, Naoya Sakatani, Rie Honda, Shingo Kameda, Hidehiko Suzuki, Yuichiro Cho, Kazuo Yoshioka, Kazunori Ogawa, Kei Shirai, Hirotaka Sawada, Seiji Sugita
    Earth, Planets and Space 75(1) 2023年8月22日  査読有り
    Abstract Zodiacal light (ZL) is sunlight scattered by interplanetary dust particles (IDPs) at optical wavelengths. The spatial distribution of IDPs in the Solar System may hold an important key to understanding the evolution of the Solar System and material transportation within it. The number density of IDPs can be expressed as $$n(r) \sim r^{-\alpha }$$, and the exponent $$\alpha \sim 1.3$$ was obtained by previous observations from interplanetary space by Helios 1/2 and Pioneer 10/11 in the 1970s and 1980s. However, no direct measurements of $$\alpha $$ based on ZL observations from interplanetary space outside Earth’s orbit have been performed since then. Here, we introduce initial results for the radial profile of the ZL at optical wavelengths observed over the range 0.76$$-$$1.06 au by ONC-T aboard the Hayabusa2# mission in 2021-2022. The ZL brightness we obtained is well reproduced by a model brightness, although there is a small excess of the observed ZL brightness over the model brightness at around 0.9 au. The radial power-law index we obtained is $$\alpha = 1.30 \pm 0.08$$, which is consistent with previous results based on ZL observations. The dominant source of uncertainty arises from the uncertainty in estimating the diffuse Galactic light (DGL). Graphical Abstract
  • Manabu Yamada, Toru Kouyama, Koki Yumoto, Eri Tatsumi, Naofumi Takaki, Yasuhiro Yokota, Tomokatsu Morota, Naoya Sakatani, Masahiko Hayakawa, Moe Matsuoka, Rie Honda, Chikatoshi Honda, Shingo Kameda, Hidehiko Suzuki, Yuichiro Cho, Kazuo Yoshioka, Kazunori Ogawa, Kei Shirai, Hirotaka Sawada, Seiji Sugita
    Earth, Planets and Space 75(1) 2023年3月13日  査読有り
    After delivering its sample capsule to Earth, the Hayabusa2 spacecraft started its extended mission to perform a flyby of asteroid 2001 CC21 in 2026 and rendezvous with asteroid 1998 KY26 in 2031. During the extended mission, the optical navigation camera (ONC) of Hayabusa2 will play an important role in navigation and science observations, but it has suffered from optical deterioration after the spacecraft's surface contact with and sampling of asteroid Ryugu. Furthermore, the sensitivity of the telescopic camera (ONC-T) has continued to decrease for more than a year, posing a serious problem for the extended mission. These are problems that could potentially be encountered by other sample-return missions involving surface contact. In this study, we evaluated the long-term variation of ONC performance over the 6.5 years following the launch in 2014 to predict how it will perform during observations of the two target asteroids in its extended mission (6 and 11 years from the Earth return, respectively). Our results showed several important long-term trends in ONC performance, such as transmission, dark noise level, and hot pixels. During the long cruising period of the extended mission, we plan to observe both zodiacal light and exoplanet transits as additional science targets. The accuracy of these observations is sensitive to background noise level and stray-light contamination, so we conducted new test observations to search for the lowest stray light, which has been found to depend on spacecraft attitude. The results of these analyses and new test observations suggest that the Hayabusa2 ONC will be able to conduct cruising, flyby, and rendezvous observations of asteroids with sufficient accuracy.
  • Hikaru Yabuta, George D. Cody, Cécile Engrand, Yoko Kebukawa, Bradley De Gregorio, Lydie Bonal, Laurent Remusat, Rhonda Stroud, Eric Quirico, Larry Nittler, Minako Hashiguchi, Mutsumi Komatsu, Taiga Okumura, Jérémie Mathurin, Emmanuel Dartois, Jean Duprat, Yoshio Takahashi, Yasuo Takeichi, David Kilcoyne, Shohei Yamashita, Alexandre Dazzi, Ariane Deniset-Besseau, Scott Sandford, Zita Martins, Yusuke Tamenori, Takuji Ohigashi, Hiroki Suga, Daisuke Wakabayashi, Maximilien Verdier-Paoletti, Smail Mostefaoui, Gilles Montagnac, Jens Barosch, Kanami Kamide, Miho Shigenaka, Laure Bejach, Megumi Matsumoto, Yuma Enokido, Takaaki Noguchi, Hisayoshi Yurimoto, Tomoki Nakamura, Ryuji Okazaki, Hiroshi Naraoka, Kanako Sakamoto, Harold C. Connolly, Dante S. Lauretta, Masanao Abe, Tatsuaki Okada, Toru Yada, Masahiro Nishimura, Kasumi Yogata, Aiko Nakato, Miwa Yoshitake, Ayako Iwamae, Shizuho Furuya, Kentaro Hatakeda, Akiko Miyazaki, Hiromichi Soejima, Yuya Hitomi, Kazuya Kumagai, Tomohiro Usui, Tasuku Hayashi, Daiki Yamamoto, Ryota Fukai, Seiji Sugita, Kohei Kitazato, Naru Hirata, Rie Honda, Tomokatsu Morota, Eri Tatsumi, Naoya Sakatani, Noriyuki Namiki, Koji Matsumoto, Rina Noguchi, Koji Wada, Hiroki Senshu, Kazunori Ogawa, Yasuhiro Yokota, Yoshiaki Ishihara, Yuri Shimaki, Manabu Yamada, Chikatoshi Honda, Tatsuhiro Michikami, Moe Matsuoka, Naoyuki Hirata, Masahiko Arakawa, Chisato Okamoto, Masateru Ishiguro, Ralf Jaumann, Jean-Pierre Bibring, Matthias Grott, Stefan Schröder, Katharina Otto, Cedric Pilorget, Nicole Schmitz, Jens Biele, Tra-Mi Ho, Aurélie Moussi-Soffys, Akira Miura, Hirotomo Noda, Tetsuya Yamada, Keisuke Yoshihara, Kosuke Kawahara, Hitoshi Ikeda, Yukio Yamamoto, Kei Shirai, Shota Kikuchi, Naoko Ogawa, Hiroshi Takeuchi, Go Ono, Yuya Mimasu, Kent Yoshikawa, Yuto Takei, Atsushi Fujii, Yu-ichi Iijima, Satoru Nakazawa, Satoshi Hosoda, Takahiro Iwata, Masahiko Hayakawa, Hirotaka Sawada, Hajime Yano, Ryudo Tsukizaki, Masanobu Ozaki, Fuyuto Terui, Satoshi Tanaka, Masaki Fujimoto, Makoto Yoshikawa, Takanao Saiki, Shogo Tachibana, Sei-ichiro Watanabe, Yuichi Tsuda
    Science 379(6634) 2023年2月24日  査読有り
    Samples of the carbonaceous asteroid (162173) Ryugu were collected and brought to Earth by the Hayabusa2 spacecraft. We investigated the macromolecular organic matter in Ryugu samples and found that it contains aromatic and aliphatic carbon, ketone, and carboxyl functional groups. The spectroscopic features of the organic matter are consistent with those in chemically primitive carbonaceous chondrite meteorites that experienced parent-body aqueous alteration (reactions with liquid water). The morphology of the organic carbon includes nanoglobules and diffuse carbon associated with phyllosilicate and carbonate minerals. Deuterium and/or nitrogen-15 enrichments indicate that the organic matter formed in a cold molecular cloud or the presolar nebula. The diversity of the organic matter indicates variable levels of aqueous alteration on Ryugu’s parent body.

MISC

 55
  • 津村耕司, 松浦周二, 佐野圭, 岩田隆浩, 岩田隆浩, 矢野創, 矢野創, 北里宏平, 瀧本幸司, 山田学, 諸田智克, 神山徹, 早川雅彦, 横田康弘, 巽瑛理, 松岡萌, 坂谷尚哉, 本田理恵, 亀田真吾, 鈴木秀彦, 長勇一郎, 吉岡和夫, 小川和律, 白井慶, 澤田弘崇, 杉田精司, 杉田精司
    日本惑星科学会秋季講演会予稿集(Web) 2023 2023年  
  • 佐々木晶, 神田志穂, 菊地紘, 道上達広, 諸田智克, 本田親寿, 宮本英昭, 逸見良道, 杉田精司, 巽瑛理, 渡邊誠一郎, 竝木則行, 平林正稔, 平田成, 中村智樹, 野口高明, 廣井孝弘, 松本晃治, 野田寛大, 坂谷尚哉, 亀田真吾, 神山徹, 鈴木秀彦, 山田学, 本田理恵, 横田康弘, 長勇一郎, 吉岡和夫, 早川雅彦, 松岡萌, 金丸仁明, 澤田弘崇, 吉川真
    日本惑星科学会秋季講演会予稿集(Web) 2020 2020年  
  • 嶌生有理, 荒川政彦, 佐伯孝尚, 門野敏彦, 高木靖彦, 和田浩二, 飯島祐一, 今村裕志, 岡本千里, 白井慶, 中澤暁, 早川雅彦, 平田成, 矢野創
    衝撃波シンポジウム講演論文集(CD-ROM) 2019 2020年  
  • 和田浩二, 石橋高, 木村宏, 荒川政彦, 澤田弘崇, 小川和律, 白井慶, 本田理恵, 飯島祐一, 門野敏彦, 坂谷尚哉, 三桝裕也, 戸田知朗, 嶌生有理, 中澤暁, 早川基, 佐伯孝尚, 高木靖彦, 今村裕志, 岡本千里, 早川雅彦, 平田成, 矢野創
    日本惑星科学会秋季講演会予稿集(Web) 2019 2019年  
  • 荒川政彦, 佐伯孝尚, 門野敏彦, 高木靖彦, 和田浩二, 飯島祐一, 今村裕志, 岡本千里, 嶌生有理, 白井慶, 中澤暁, 早川雅彦, 平田成, 矢野創, 澤田弘崇, 小川和律, 石橋高, 木村宏, 小林正規, 坂谷尚哉, 早川基, 本田理恵, 杉田精司, 諸田智克, 亀田真吾, 巽瑛理, 本田親寿, 横田康弘, 神山徹, 山田学, 鈴木秀彦, 吉岡和夫, 長勇一郎, 松岡萌
    日本惑星科学会秋季講演会予稿集(Web) 2019 2019年  

書籍等出版物

 2

講演・口頭発表等

 217

所属学協会

 3

共同研究・競争的資金等の研究課題

 10