13 citations · 17 across the 16 of their papers we have counts for
17 papers
Spectral Energy Distribution and Polarimetric Properties of Dust in the Interstellar Comet 3I/ATLAS
Seungwon Choi, Masateru Ishiguro, Hiroyuki Naito +13
The interstellar comet 3I/ATLAS exhibits unusual polarimetric properties compared with Solar System comets, while constraints on its fundamental physical properties, such as dust a…
Dark asteroids exhibiting intermediate characteristics between C and X types
Sunao Hasegawa, Chrysa Avdellidou, Michael Marsset +8
Large main-belt asteroids with visible geometric albedos below 0.1 are predominantly classified within the C- and X-complex spectroscopic classes. C-type and dark X-type asteroids…
Dust Properties of the Interstellar Object 3I/ATLAS Revealed by Optical and Near-Infrared Polarimetry
Seungwon Choi, Masateru Ishiguro, Jun Takahashi +17
We present independent polarimetric observations of the interstellar object 3I/ATLAS, including the first near-infrared polarimetric measurements. Using imaging polarimeters, we me…
Pre-perihelion Emergence of the CN Gas Coma in 3I/ATLAS Temporally and Spatially Resolved by the 7-Dimensional Telescope
Gregory S. H. Paek, Myungshin Im, Mankeun Jeong +8
We present time-series medium-band (R~20-40) observations of the third interstellar object 3I/ATLAS (C/2025 N1) obtained with the 7-Dimensional Telescope (7DT), enabling spatially…
SOLO: wide-field asteroid light curve monitoring system for SPHEREx
Bumhoo Lim, Seungwon Choi, Yoonsoo P. Bach +8
We present the Solar system Objects Light curve Observatory (SOLO), a wide-field, high-cadence optical survey system designed to obtain absolutely calibrated asteroid light curves,…
SQUIDPOL: Seoul National University QUadruple Imaging Device for POLarimetry
Sunho Jin, Jooyeon Geem, Masateru Ishiguro +9
We present SQUIDPOL, a low-cost, multi-channel optical imaging polarimeter that performs simultaneous linear polarization measurements using a rotating half-wave plate, a non-polar…
SPHEREx Pre-Perihelion Mapping of , , and in Interstellar Object 3I/ATLAS
Carey M. Lisse, Yoonsoo P. Bach, Brendan P. Crill +35
From 01- to 15-Aug-2025UT, the SPHEREx spacecraft observed interstellar object 3I/ATLAS. Using spectrophotometry at m, light curves, spectra, and imaging of…
Resonant structures in exozodiacal clouds created by exo-Earths in the habitable zone of late-type stars
Seung-Yoo Lee, Masateru Ishiguro, Hangbin Jo +1
Earth-like exoplanets can create resonant structures in exozodiacal dust through mean motion resonances (MMRs). These structures not only suggest the presence of such planets, but…
Simulation of Impact-induced seismic shaking on asteroid (25143) Itokawa to address its resurfacing process
Sunho Jin, Masateru Ishiguro
The surface of asteroid (25143) Itokawa shows both fresh and mature terrains, despite its short space weathering timescale of approximately 1000 years, as inferred from recent stud…
Optical and Near-Infrared Contemporaneous Polarimetry of C/2023 A3 (Tsuchinshan-ATLAS)
Bumhoo Lim, Masateru Ishiguro, Jun Takahashi +11
We conducted contemporaneous optical and near-infrared polarimetric and spectroscopic observations of C/2023 A3 (Tsuchinshan-ATLAS, hereafter T-A) from 2024 October 16 to December…
Surface dynamics and geophysical environment of asteroid (3200) Phaethon
Hangbin Jo, Masateru Ishiguro, Derek C. Richardson +3
Context. (3200) Phaethon is a ~5-km-diameter near-Earth asteroid with a small perihelion distance of 0.14 au and is the parent body of the Geminids. JAXA's DESTINY+ mission will fl…
Enlargement of depressions on comet 81P/Wild 2: Constraint based on 30-year cometary activity in the inner Solar System
Bumhoo Lim, Masateru Ishiguro
Context. The Stardust flyby mission to Jupiter-family comet (JFC) 81P/Wild 2 (hereafter, 81P) captured its dense quasicircular depressions. Nevertheless, the formation mechanism re…
New evidence supporting past dust ejections from active asteroid (4015) Wilson-Harrington
Sunho Jin, Masateru Ishiguro, Jooyeon Geem +15
Context. (4015) Wilson-Harrington (hereafter, WH) was discovered as a comet in 1949 but has a dynamical property consistent with that of a near-Earth asteroid. Although there is a…
Study of hydrated asteroids via their polarimetric properties at low phase angles
Jooyeon Geem, Masateru Ishiguro, Hiroyuki Naito +11
Context. Ch-type asteroids are distinctive among other dark asteroids in that they exhibit deep negative polarization branches (NPBs). Nevertheless, the physical and compositional…
Dynamical study of Geminid formation assuming a rotational instability scenario
Hangbin Jo, Masateru Ishiguro
Context: Various ideas have been proposed to explain the formation of the Geminid meteoroid stream from the asteroid (3200) Phaethon. However, little has been studied about the Gem…
Multicolor Photometry of Tiny Near-Earth Asteroid 2015 RN Across a Wide Range of Phase Angles: Possible Mission Accessible A-type Asteroid
Jin Beniyama, Ryou Ohsawa, Chrysa Avdellidou +10
Studying small near-Earth asteroids is important to understand their dynamical histories and origins as well as to mitigate the damage of the asteroid impact to the Earth. We repor…
Optical observations of NEA 162173 (1999 JU3) during the 2011-2012 apparition
M. -J. Kim, Y. -J. Choi, H. -K. Moon +7
Near-Earth asteroid 162173 (1999 JU3) is a potential target of two asteroid sample return missions, not only because of its accessibility but also because of the first C-type aster…