3 papers
astro-ph.EP2026
Opposition effect of comet 28P/Neujmin observed with Subaru Hyper Suprime-Cam
Takafumi Ootsubo, Hideyo Kawakita, Tadafumi Takata +8
We present an observational study of the nucleus of comet 28P/Neujmin at a heliocentric distance exceeding 10 au, where coma contamination is effectively minimized. Observations we…
astro-ph.EP2026
The first detection of an atmosphere on a trans-Neptunian object beyond Pluto
Ko Arimatsu, Fumi Yoshida, Tsutomu Hayamizu +4
Trans-Neptunian objects (TNOs) in the outer Solar System are predominantly small, icy worlds long presumed to be atmosphereless except for the largest bodies. Until now, Pluto has…
astro-ph.GA2026
A post-perihelion constraint on the CO/HO ratio of interstellar comet 3I/ATLAS from [O I] forbidden lines
Yoshiharu Shinnaka, Ko Tsujimoto, Hideyo Kawakita +3
We present high-resolution optical spectroscopy of interstellar comet 3I/ATLAS (C/2025 N1) obtained with the High Dispersion Spectrograph mounted on the Subaru Telescope on UT 2026…