activity
20242026
collaborators

7 papers

astro-ph.EP2026

Simultaneous Tricolor Video Observations of Three Tiny Near-Earth Asteroids with Sub-Minute Rotation Periods

Jin Beniyama, Ryou Ohsawa, Shigeyuki Sako +4

Studying the physical properties of near-Earth asteroids (NEAs) is crucial for understanding their dynamical histories and origins, and assessing impact hazards to Earth. Tiny NEAs…

astro-ph.HE2026

Spectral and photometric variability of SS 433 observed with XRISM and simultaneous optical and near-infrared telescopes

Yusuke Sakai, Shinya Yamada, Yuta Okada +36

We present results from coordinated multiwavelength observations of the SS 433, obtained with XRISM, optical telescopes, and near-infrared camera during 2024 April and 2025 March.…

astro-ph.EP2026

An optical transient candidate of 2-second duration captured by wide-field video observations

Noriaki Arima, Mamoru Doi, Shigeyuki Sako +14

Recent time-domain surveys have revealed rapid transients that evolve on timescales of days, expanding the transient population into the short-duration regime. The tr…

astro-ph.HE2025

Multiband Optical Photometric and Spectroscopic Monitoring of the 2024 Flare Event in Transition Blazar OP313

TianFang Zhang, Mitsuru Kokubo, Mamoru Doi +19

Blazars are active galactic nuclei known for their extreme variability, offering unique opportunities to study jet physics and high-energy emission mechanisms. In 2024, the Flat Sp…

astro-ph.EP2025

Second-timescale Glints from Satellites and Space Debris Detected with Tomo-e Gozen

Masaomi Tanaka, Ichiro Takahashi, Naoki Yoshida +17

A search for second-timescale optical transients is one of the frontiers of time-domain astronomy. However, it has been pointed out that reflections of sunlight from Earth-orbiting…

astro-ph.HE2025

Evolution of the inner accretion flow and the white-dwarf spin pulse during the 2023 outburst in GK Persei

Mariko Kimura, Takayuki Hayashi, Yuuki Wada +8

We present our X-ray and optical observations performed by NICER, NuSTAR, and Tomo-e Gozen during the 2023 outburst in the intermediate polar GK Persei. The X-ray spectrum consiste…