Kei E. I. Tanaka

Assistant Professor
Department of Earth and Planetary Sciences
Institute of Science Tokyo

Welcome to my page!

I’m an astronomer studying the birth of stars and planets

Recent Topics

• Sep 10, 2025: Our work featured on NASA JWST webpage!
  Our recent paper on the LZ-STAR survey of Sh2-284 was highlighted on the NASA JWST science news page. The JWST image shows an immense stellar jet extending over 8 light-years, providing striking evidence of ordered massive star formation in the outer Galaxy.

• Sep 10, 2025: Paper Published! Cheng et al. 2025, ApJ
  Our paper on the LZ-STAR survey of the low-metallicity region Sh2-284 has been published. Using JWST and ALMA, we reported ordered massive star formation with large bipolar outflows in one of the lowest-metallicity star-forming regions of our Galaxy.

• Aug 25, 2025: Paper Published! Yamamuro et al. 2025, ApJ
  We developed a self-consistent model of grain growth and millimeter-wave emission in massive protostellar disks. A comparison with ALMA observations suggests that silicate grain coagulation may be suppressed in these high-temperature environments.

• Aug 20, 2025: Paper Published! Olguin et al. 2025, Sci. Adv
  Our paper on ALMA observations of the massive star-forming region G336.01 has been published. We discovered massive extended streamers feeding a massive protostar, providing direct evidence of large-scale inflows that sustain its growth.

• Aug 4, 2025: Paper Published! Zhen et al. 2025, A&A
  Our paper on ALMA observations of the massive star-forming region I18308 has been published. We revealed hierarchical fragmentation in a hub-filament system, linking large-scale structures to the formation of massive stars.

• July 29, 2025: Press Release! “Discovery of Protostellar Outflows in the Outer Galaxy – Approaching the Universality of Star Formation in the Outer Milky Way”
  The press release on our recent paper was issued from Niigata Univ (Japanese only).

• July 17, 2025: Paper Published! Ikeda et al. 2025, ApJ
  Our paper on ALMA observations of a protostar in the outer Galaxy has been published. We reported the first detection in this region of a well-collimated jet accompanied by a wider molecular outflow.

• Mar 31, 2025: Dr. Patricio Sanhueza was promoted to Associate Professor at the University of Tokyo and left Science Tokyo!

• Mar 4, 2025: KAKENHI Scientific Research (C) Project Accepted
  The project “Establishing the Science of Hot Disks in Massive Star Formation” has been selected for funding under the KAKENHI Grant-in-Aid for Scientific Research (C) program.

• Feb 24, 2025: Paper Accepted! Telkamp, Fedriani et al. 2025, ApJ
  Based on SOFIA observations and statistical analysis of protostars in clustered star-forming regions, we found a dearth of ≳30 M☉ protostars, suggesting that cluster environments may suppress the formation of the most massive stars.

• Jan 6, 2025: Paper Accepted! Tokuda et al. 2025, ApJ
  Our paper on the ALMA observations of 17 massive protostars in the Small Magellanic Cloud has been accepted. We discovered filamentary structures in about 60% of the observed regions, along with signs of their evolutionary transitions, offering new insights into massive star formation under low-metallicity conditions.

• Nov 11, 2024: Recruitment for a Project Assistant Professor for the ALMA Joint Scientific Research Program!
  The NAOJ ALMA Project has begun recruiting a Project Assistant Professor at Science Tokyo to work on the project titled “The Battle between Accretion and Feedback in Massive Star Formation.”

• Oct 25, 2024: Paper Accepted! Taniguchi et al. 2024, A&A
  Our paper on carbon-chain chemistry using Yebes data has been accepted. Warm Carbon-Chain Chemistry was also confirmed in intermediate-mass stars.

• Oct 8, 2024: Approved for the ALMA Joint Scientific Research Program
  My proposal "The Battle between Accretion and Feedback in Massive Star Formation" for ALMA Joint Scientific Research Program has been approved. 

• Oct 1, 2024: Science Tokyo kicks off!
  The Institute of Science Tokyo is established, following the merger of Tokyo Medical and Dental University and Tokyo Institute of Technology.