Barosch, Jens; Nittler, Larry R.; Wang, Jianhua; Alexander, Conel M. O'D; De Gregorio, Bradley T.; Engrand, Cecile; Kebukawa, Yoko; Nagashima, Kazuhide; Stroud, Rhonda M.; Yabuta, Hikaru; Abe, Yoshinari; Aleon, Jerome; Amari, Sachiko; Amelin, Yuri; Bajo, Ken-ichi; Bejach, Laure; Bizzarro, Martin; Bonal, Lydie; Bouvier, Audrey; Carlson, Richard W.; Chaussidon, Marc; Choi, Byeon-Gak; Cody, George D.; Dartois, Emmanuel; Dauphas, Nicolas; Davis, Andrew M.; Dazzi, Alexandre; Deniset-Besseau, Ariane; Di Rocco, Tommaso; Duprat, Jean; Fujiya, Wataru; Fukai, Ryota; Gautam, Ikshu; Haba, Makiko K.; Hashiguchi, Minako; Hibiya, Yuki; Hidaka, Hiroshi; Homma, Hisashi; Hoppe, Peter; Huss, Gary R.; Ichida, Kiyohiro; Iizuka, Tsuyoshi; Ireland, Trevor R.; Ishikawa, Akira; Ito, Motoo; Itoh, Shoichi; Kamide, Kanami; Kawasaki, Noriyuki; Kilcoyne, A. L. David; Kita, Noriko T.; Kitajima, Kouki; Kleine, Thorsten; Komatani, Shintaro; Komatsu, Mutsumi; Krot, Alexander N.; Liu, Ming-Chang; Martins, Zita; Masuda, Yuki; Mathurin, Jeremie; McKeegan, Kevin D.; Montagnac, Gilles; Morita, Mayu; Mostefaoui, Smail; Motomura, Kazuko; Moynier, Frederic; Nakai, Izumi; Nguyen, Ann N.; Ohigashi, Takuji; Okumura, Taiga; Onose, Morihiko; Pack, Andreas; Park, Changkun; Piani, Laurette; Qin, Liping; Quirico, Eric; Remusat, Laurent; Russell, Sara S.; Sakamoto, Naoya; Sandford, Scott A.; Schonbachler, Maria; Shigenaka, Miho; Suga, Hiroki; Tafla, Lauren; Takahashi, Yoshio; Takeichi, Yasuo; Tamenori, Yusuke; Tang, Haolan; Terada, Kentaro; Terada, Yasuko; Usui, Tomohiro; Verdier-Paoletti, Maximilien; Wada, Sohei; Wadhwa, Meenakshi; Wakabayashi, Daisuke; Walker, Richard J.; Yamashita, Katsuyuki; Yamashita, Shohei; Yin, Qing-Zhu; Yokoyama, Tetsuya; Yoneda, Shigekazu; Young, Edward D.; Yui, Hiroharu; Zhang, Ai-Cheng; Abe, Masanao; Miyazaki, Akiko; Nakato, Aiko; Nakazawa, Satoru; Nishimura, Masahiro; Okada, Tatsuaki; Saiki, Takanao; Tanaka, Satoshi; Terui, Fuyuto; Tsuda, Yuichi; Watanabe, Sei-ichiro; Yada, Toru; Yogata, Kasumi; Yoshikawa, Makoto; Nakamura, Tomoki; Naraoka, Hiroshi; Noguchi, Takaaki; Okazaki, Ryuji; Sakamoto, Kanako; Tachibana, Shogo; Yurimoto, Hisayoshi
2022
ASTROPHYSICAL JOURNAL LETTERS
DOI
10.3847/2041-8213/ac83bd
We have conducted a NanoSIMS-based search for presolar material in samples recently returned from C-type asteroid Ryugu as part of JAXA's Hayabusa2 mission. We report the detection of all major presolar grain types with O- and C-anomalous isotopic compositions typically identified in carbonaceous chondrite meteorites: 1 silicate, 1 oxide, 1 O-anomalous supernova grain of ambiguous phase, 38 SiC, and 16 carbonaceous grains. At least two of the carbonaceous grains are presolar graphites, whereas several grains with moderate C isotopic anomalies are probably organics. The presolar silicate was located in a clast with a less altered lithology than the typical extensively aqueously altered Ryugu matrix. The matrix- normalized presolar grain abundances in Ryugu are 4.8(-2.6)(+4.7) ppm for O-anomalous grains, 25(-)(5)(+)(6) ppm for SiC grains, and 11(-3)(+5) ppm for carbonaceous grains. Ryugu is isotopically and petrologically similar to carbonaceous Ivuna-type (CI) chondrites. To compare the in situ presolar grain abundances of Ryugu with CI chondrites, we also mapped Ivuna and Orgueil samples and found a total of 15 SiC grains and 6 carbonaceous grains. No O-anomalous grains were detected. The matrix-normalized presolar grain abundances in the CI chondrites are similar to those in Ryugu: 23(-6)(+7) ppm SiC and 9.0 (+5.4)(-3)(.6) ppm carbonaceous grains. Thus, our results provide further evidence in support of the Ryugu-CI connection. They also reveal intriguing hints of small-scale heterogeneities in the Ryugu samples, such as locally distinct degrees of alteration that allowed the preservation of delicate presolar material.