[17] "White Dwarf Mergers and the Historical SN 1181", ITC Luncheon, CfA | Harvard & Smithsonian, MA, USA (Nov 2025)
[16] "Modeling Pre-"supernova" Activity of Binary Undergoing Merger", AAS264 (Special session), Alaska, USA (slides, Jun 2025)
[15] "Extreme Transients from Massive Star Binaries" , Explosive Astro Seminar, UC Berkley, CA, USA (April 2025)
[14] "Luminous Supernova Precursors from Close Binaries", CfA Seminar, CfA | Harvard & Smithsonian, MA, USA (slides, Oct 2024)
[13] "Creating the Dense Circumstellar Matter of SN 2023ixf", SN 2023ixf, The Decadal Supernova in M101 Workshop, ESO, Germany (Jun 2024)
[12] "Modeling Precursors of Core-collapse Supernovae", UTokyo Komaba Astro Group Seminar, Japan (slides, Sept 2023)
[11] "The Decadal SN 2023ixf: (My Personal) Thoughts", Israel-Japan Transient Theory Workshop, UTokyo, Japan (Sept 2023)
[10] "X-ray View of the Transient Zoo (in Japanese)", Japan High-energy Astrophysics Association Conference (slides, Mar 2023)
[9] "Violent Eruptions just before the Death of Massive Stars", Waseda University, Japan (online, May 2022)
[8] "Multi-wavelength Emissions from Supernovae with Circumstellar Interaction", NAOJ, Japan (Mar 2022)
[7] "Multi-wavelength Emissions from Supernovae with Circumstellar Interaction", Stockholm University, Sweden (online, Oct 2021)
[6] "Multi-wavelength Emissions from Supernovae with Circumstellar Interaction", HEPAP/CMA Seminar, Penn State University, USA (online, Sep 2021)
[5] "Observing the Traces of Black Hole Formation", CCAPP Astroparticle Lunch, Ohio State University, USA (online, Sep 2021)
[4] "Peculiar Optical Transients from Newborn Black Holes?", YITP seminar, Kyoto University, Japan (Jun 2021)
[3] "Peculiar Optical Transients from Newborn Black Holes?" Albert Einstein Institute at Potsdam, Germany (online, Jun 2021)
[2] "Emissions from Explosive Transients and Multi-messenger Astronomy", University of Florida, USA (Sep 2019)
[1] "Observing Stellar-mass Black Holes in the Nearby Universe", RESCEU Joint Seminar, University of Tokyo, Japan (Jul 2018)
[3] "Gaia Black Holes: One, Two and Three", Carnegie Observatories Theory Talk (May 2024) [notes]
[2] "Overview and (my personal) thoughts on SN 2023ixf", Carnegie Observatories SN meeting (July 2023) [notes]
[1] "Circumstellar Matter in Interacting Supernovae and Their Radiative Acceleration", Carnegie Observatories SN meeting (Jan 2023) [notes]
Supernova exhibited long-lasting pre-explosion activity, in Phys.org [link]
Fresh wind blows from Historical Supernova 1181, UTokyo Press Release [link]
Getting to Know the Supernova Next Door: SN 2023ixf, in AAS Nova [link]
Can Astronomers Predict Which Stars are About to Explode as Supernovae?, in Universe Today [link]
Millions of Black Holes Are Hiding in the Milky Way Eating Matter from Interstellar Space, in Newsweek [link]
Science summary for "All-sky search for Short Duration Gravitational Wave Transients in the Second Advanced LIGO Observing Run" [link]
Science summary for "Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run" [link]
Jude McLean (2025-; undergrad at Caltech). On high-redshift black holes (w/ Phil Hopkins)
Kazuma Kato (2023-; undergrad at Tohoku Univ). On long-rising supernovae
Adrian Helmling-Cornell (2024-25; PhD student at UOregon). On cosmic string search with LIGO/Virgo O4 data
Emily Hu (2023-24; undergrad at Caltech). On black hole - helium star binaries (w/ Linhao Ma, Jim Fuller)
Daiki Watarai (2023-24; PhD student at UTokyo). On inferring supermassive black hole (BH) spins by of BH merger ringdowns (w/ Naritaka Oshita)
Minori Shikauchi (2022-23; PhD student at UTokyo). On BH binaries detectable with Gaia (w/ Ataru Tanikawa, Norita Kawanaka)
Takatoshi Ko (2021-; Master & PhD student at UTokyo). On interacting supernovae [paper1, paper2], on WD merger remnants and SN1181 [paper1, paper2]
Tomoki Terasaki (2019-20; undergrad at UTokyo). On using AT2018cow-like transients as probes for reionization
VLA/24B-095 "Resolving the nature of a merger-made white dwarf inside the remnant of SN 1181" (co-I; PI: T. Ko), 11 hr
VLA/25B-120, ditto (co-I; PI: T. Ko), 8.2 hr
Chandra cycle 27 (co-I, theory lead; PI: H. Suzuki), 39ks
Referee for Journals ApJ, ApJ Letters, A&A, MNRAS, PASJ, Galaxies, Universe (2020-)
Reviewer for Observing Proposals (confidential; 2025)
Organizer, Caltech Monday Pizza Lunch Discussion (Oct 2023 - May 2025)
Organizer, Caltech TAPIR Seminar (Jan 2023 - May 2025)
Astronomy on Tap Los Angeles speaker (July 2025)
Organized (informal) conference for young researchers at UTokyo Hongo Campus (Mar 2023)
Organizing Member, University of Tokyo Open Campus for High School Students (Aug 2022)
Initiator/Main Developer of open-source code CHIPS (Complete History of Interaction-Powered Supernovae).
Developed dust physics in a semi-analytical galaxy modeling code A-SLOTH (Ancient Stars and Local Observables by Tracing Haloes).
Developed data analysis pipeline for bursts from cosmic strings in gravitational-wave detector data.
Open Softwares: MESA (stellar evolution), Cloudy (radiative transfer), SNEC (rad-hydro for supernovae), Athena++ (multi-D hydro), A-SLOTH (semi-analytical galaxy formation), lalsuite (GW data analysis)
Programming languages: Python, C++, C, Fortran (from most to least frequent usage)
Other: git, mathematica, sqlite
Japanese (mother tongue)
English (fluent, lived 5yrs of childhood in Los Angeles)
Chinese (learned 2yrs under UTokyo's Trilingual Program (TLP); HSK-5 230/300)