Presolar stardust in asteroid Ryugu
Creators: name: Barosch, Jens
name: Nittler, Larry R.
name: Wang, Jianhua
name: Alexander, Conel M. O'D.
name: De Gregorio, Bradley T.
name: Engrand, Cécile
name: Kebukawa, Yoko
name: Nagashima, Kazuhide
name: Stroud, Rhonda M.
name: Yabuta, Hikaru
name: Abe, Yoshinari
name: Aléon, Jérôme
name: Amari, Sachiko
name: Amelin, Yuri
name: Bajo, Ken-ichi
name: Bejach, Laure
name: Bizzarro, Martin
name: Bonal, Lydie
name: Bouvier, Audrey
name: Carlson, Richard W.
name: Chaussidon, Marc
name: Choi, Byeon-Gak
name: Cody, George D.
name: Dartois, Emmanuel
name: Dauphas, Nicolas
name: Davis, Andrew M.
name: Dazzi, Alexandre
name: Deniset-Besseau, Ariane
name: Di Rocco, Tommaso
name: Duprat, Jean
name: Fujiya, Wataru
name: Fukai, Ryota
name: Gautam, Ikshu
name: Haba, Makiko K.
name: Hashiguchi, Minako
name: Hibiya, Yuki
name: Hidaka, Hiroshi
name: Homma, Hisashi
name: Hoppe, Peter
name: Huss, Gary R.
name: Ichida, Kiyohiro
name: Iizuka, Tsuyoshi
name: Ireland, Trevor R.
name: Ishikawa, Akira
name: Ito, Motoo
name: Itoh, Shoichi
name: Kamide, Kanami
name: Kawasaki, Noriyuki
name: Kilcoyne, A. L. David
name: Kita, Noriko T.
name: Kitajima, Kouki
name: Kleine, Thorsten
name: Komatani, Shintaro
name: Komatsu, Mutsumi
name: Krot, Alexander N.
name: Liu, Ming-Chang
name: Martins, Zita
name: Masuda, Yuki
name: Mathurin, Jérémie
name: McKeegan, Kevin D.
name: Montagnac, Gilles
name: Morita, Mayu
name: Mostefaoui, Smail
name: Motomura, Kazuko
name: Moynier, Frédéric
name: Nakai, Izumi
name: Nguyen, Ann N.
name: Ohigashi, Takuji
name: Okumura, Taiga
name: Onose, Morihiko
name: Pack, Andreas
name: Park, Changkun
name: Piani, Laurette
name: Qin, Liping
name: Quirico, Eric
name: Remusat, Laurent
name: Russell, Sara S.
name: Sakamoto, Naoya
name: Sandford, Scott A.
name: Schönbächler, Maria
name: Shigenaka, Miho
name: Suga, Hiroki
name: Tafla, Lauren
name: Takahashi, Yoshio
name: Takeichi, Yasuo
name: Tamenori, Yusuke
name: Tang, Haolan
name: Terada, Kentaro
name: Terada, Yasuko
name: Usui, Tomohiro
name: Verdier-Paoletti, Maximilien
name: Wada, Sohei
name: Wadhwa, Meenakshi
name: Wakabayashi, Daisuke
name: Walker, Richard J.
name: Yamashita, Katsuyuki
name: Yamashita, Shohei
name: Yin, Qing-Zhu
name: Yokoyama, Tetsuya
name: Yoneda, Shigekazu
name: Young, Edward D.
name: Yui, Hiroharu
name: Zhang, Ai-Cheng
name: Abe, Masanao
name: Miyazaki, Akiko
name: Nakato, Aiko
name: Nakazawa, Satoru
name: Nishimura, Masahiro
name: Okada, Tatsuaki
name: Saiki, Takanao
name: Tanaka, Satoshi
name: Terui, Fuyuto
name: Tsuda, Yuichi
name: Watanabe, Sei-ichiro
name: Yada, Toru
name: Yogata, Kasumi
name: Yoshikawa, Makoto
name: Nakamura, Tomoki
name: Naraoka, Hiroshi
name: Noguchi, Takaaki
name: Okazaki, Ryuji
name: Sakamoto, Kanako
name: Tachibana, Shogo
name: Yurimoto, Hisayoshi
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: 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$^{+4.7}_{-2.6}$ ppm for O-anomalous grains, 25$^{+6}_{-5}$ ppm for SiC grains and 11$^{+5}_{-3}$ 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 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 $^{+7}_{-6}$ ppm SiC and 9.0$^{+5.3}_{-4.6}$ 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.
description: 12 pages, 3 figures, 2 tables. Published in ApJL