Chief Scientist Laboratories Star and Planet Formation Laboratory
Chief Scientist: Nami Sakai (Ph.D.)
Research Summary

Star and planet formation is one of the most fundamental structure-formation processes in the universe. By use of the state-of-the-art radio telescopes including ALMA, we are investigating when a disk structure is formed around a solar-type protostar, and how it is evolved into a protoplanetary disk and eventually to a planetary system. This is an essential question deeply related to the origin of the Solar system. We particularly focus on a relation between physical evolution and chemical evolution during star and planet formation. Related laboratory spectroscopic studies in the millimeter and submillimeter regimes are also planned.
Main Research Fields
- Mathematical & Physical Sciences
Related Research Fields
- Interdisciplinary Science & Engineering
- Chemistry
- Astronomy
- Physics
- Earth and planetary science
Keywords
- Star formation
- Planetary system formation
- Radio astronomy
- Astrochemistry
- Spectroscopy
Selected Publications
Papers with an asterisk(*) are based on research conducted outside of RIKEN.
- 1.
Yichen Zhang, Jonathan C. Tan, Nami Sakai, Kei E. I. Tanaka, James M. De Buizer, Mengyao Liu, Maria T. Beltran, Kaitlin Kratter, Diego Mardones, and Guido Garay.:
"An Ordered Envelope-Disk Transition in the Massive Protostellar Source G339.88-1.26"
ApJ, 873, 73, 29pp (2019) - 2.
Nami Sakai, Tomoyuki Hanawa, Yichen Zhang, Aya E. Higuchi, Satoshi Ohashi, Yoko Oya, and Satoshi Yamamoto.:
"A warped disk around an infant protostar"
Nature, 565, p206-208 (2019) - 3.
Yuji Ebisawa, Nami Sakai, Karl M. Menten, and Satoshi Yamamoto.:
"The Effect of Far-infrared Radiation on the Hyperfine Anomaly of the OH 18cm Transition"
ApJ, 871, 89, 28pp (2019) - 4.
Aya E. Higuchi, Nami Sakai, Yoshimasa Watanabe, Ana Lopez-Sepulcre, Kento Yoshida, Yoko Oya, Muneaki Imai, Yichen Zhang, Cecilia Ceccarelli, Bertrand Lefloch, Claudio Codella, Rafael Bachiller, Tomoya Hirota, Takeshi Sakai, and Satoshi Yamamoto.:
"Chemical Survey toward Young Stellar Objects in the Perseus Molecular Cloud Complex"
ApJ, Suppl. Ser., 236, 52, 25pp (2018) - 5.
Satoshi Ohashi, Patricio Sanhueza, Nami Sakai, Ryo Kandori, Minho Choi, Tomoya Hirota, Quang Nguyễn-Lu'o'ng, and Ken'ichi Tatematsu.:
"Gravitationally Unstable Condensations Revealed by ALMA in the TUKH122 Prestellar Core in the Orion A Cloud"
ApJ, 856, 147, 12pp (2018) - 6.
Tatsuya Soma, Nami Sakai, Yoshimasa Watanabe, and Satoshi Yamamoto.:
"Complex Organic Molecules in Taurus Molecular Cloud-1"
ApJ, 854, 116, 11pp (2018) - 7.
Aya E. Higuchi, Aki Sato, Takashi Tsukagoshi, Nami Sakai, Kazunari Iwasaki, Munetake Momose, Hiroshi Kobayashi, Daisuke Ishihara, Sakae Watanabe, Hidehiro Kaneda, and Satoshi Yamamoto.:
"Detection of Submillimeter-wave [CI] Emission in Gaseous Debris Disks of 49 Ceti and βPictoris"
ApJ, Lett., 839, L14, 6pp (2017) - 8.
Nami Sakai, Yoko Oya, Aya E. Higuchi, Yuri Aikawa, Tomoyuki Hanawa, Cecilia Ceccarelli, Bertrand Lefloch, Ana Lopez-Sepulcre, Yoshimasa Watanabe, Takeshi Sakai, Tomoya Hirota, Emmanuel Caux, Charlotte Vastel, Claudine Kahane, and Satoshi Yamamoto.:
"Vertical structure of the transition zone from infalling rotating envelope to disc in the Class 0 protostar, IRAS 04368+2557"
MNRAS 467, L76-L80 (2017) - 9.
*Nami Sakai, Takeshi Sakai, Tomoya Hirota, Yoshimasa Watanabe, Cecilia Ceccarelli, Claudine Kahane, Sandrine Bottinelli, Emmanuel Caux, Karine Demyk, Charlotte Vastel, Audrey Cautens, Vianney Taquet, Nagayoshi Ohashi, Shigehisa Takakuwa, His-Wei Yen, Yuri Aikawa, and Satoshi Yamamoto.:
"Change in the chemical composition of infalling gas forming a disk around a protostar"
Nature, 507, p78-80 (2014) - 10.
*Nami Sakai and Satoshi Yamamoto.:
"Warm Carbon-Chain Chemistry"
Chem. Rev., 113, p8981-9015 (2013)
Recent Research Results
Mar. 17, 2023
Space telescope probes chemistry around a newborn starNov. 22, 2022
Nascent gas giant planets may be lurking in dusty diskJan. 1, 2019
Early protostar already has a warped diskApr. 12, 2017
Collisions generate gas in debris disks
Annual research report
Related Links
Lab Members
Principal investigator
- Nami Sakai
- Chief Scientist
Core members
- Yao-Lun Yang
- Research Scientist
- Takahiro Oyama
- Research Scientist
- Satoshi Ohashi
- Research Scientist
- Akemi Tamanai
- Research Scientist
- Shota Notsu
- Special Postdoctoral Researcher
- Nadia Mariel Murillo Mejias
- Special Postdoctoral Researcher
- Yui Kawashima
- Special Postdoctoral Researcher
- Ryosuke Tominaga
- Special Postdoctoral Researcher
- Yuki Okoda
- Special Postdoctoral Researcher
- Ross Alexander Burns
- Special Postdoctoral Researcher
- Ziwei Zhang
- Postdoctoral Researcher
- Shaoshan Zeng
- Postdoctoral Researcher
- Yoshimasa Watanabe
- Visiting Scientist
- Yichen Zhang
- Visiting Scientist
- Ryohei Nakatani
- Visiting Scientist
Contact Information
S407 Chemistry and Materials Physics Building,
2-1 Hirosawa,
Wako, Saitama
351-0198, Japan
Email: nami.sakai [at] riken.jp