36 citations · 171 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…
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…
Multi-epoch spectro-photometric characterization of the minimoon 2024 PT in the visible and near-infrared
Jin Beniyama, Bryce T. Bolin, Alexey V. Sergeyev +5
2024 PT is a tiny ( m) near-Earth asteroid (NEA) discovered in August 2024. 2024 PT was gravitationally bound to the Earth-Moon system from September to November 2…
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…
Photometry and Polarimetry of 2010 XC: Observational Confirmation of E-type Near-Earth Asteroid Pair
Jin Beniyama, Shigeyuki Sako, Katsuhito Ohtsuka +16
Asteroid systems such as binaries and pairs are indicative of physical properties and dynamical histories of the Small Solar System Bodies. Although numerous observational and theo…
Multicolor and multi-spot observations of Starlink's Visorsat
Takashi Horiuchi, Hidekazu Hanayama, Masatoshi Ohishi +25
This study provides the results of simultaneous multicolor observations for the first Visorsat (STARLINK-1436) and the ordinary Starlink satellite, STARLINK-1113 in the , , $…
Spectral Type and Geometric Albedo of (98943) 2001 CC21, the Hayabusa2# Mission Target
Jooyeon Geem, Masateru Ishiguro, Mikael Granvik +18
We conducted optical polarimetry and near-infrared spectroscopy of JAXA's Hayabusa2# mission target, (98943) 2001 CC21, in early 2023. Our new observations indicated that this aste…
Morpho-kinematic modeling of the expanding ejecta of the extremely slow nova V1280 Scorpii
Hiroyuki Naito, Akito Tajitsu, Valèrio A. R. M. Ribeiro +10
Morphology of nova ejecta is essential for fully understanding the physical processes involved in nova eruptions. We studied the 3D morphology of the expanding ejecta of the extrem…
Polarimetric Properties of the Near--Sun Asteroid (155140) 2005 UD in Comparison with Other Asteroids and Meteoritic Samples
Masateru Ishiguro, Yoonsoo P. Bach, Jooyeon Geem +26
The investigation of asteroids near the Sun is important for understanding the final evolutionary stage of primitive solar system objects. A near-Sun asteroid, (155140) 2005 UD, ha…
A polarimetric study of asteroids in comet-like orbits
Jooyeon Geem, Masateru Ishiguro, Yoonsoo P. Bach +16
Context. Asteroids in comet-like orbits (ACOs) consist of asteroids and dormant comets. Due to their similar appearance, it is challenging to distinguish dormant comets from ACOs v…
Implications of High Polarization Degree for the Surface State of Ryugu
Daisuke Kuroda, Jooyeon Geem, Hiroshi Akitaya +19
The asteroid exploration project "Hayabusa2" has successfully returned samples from the asteroid (162173) Ryugu. In this study, we measured the linear polarization degrees of Ryugu…
Type Ia SN 2019ein: New Insights into the Similarities and diversities among High-Velocity SNe Ia
Miho Kawabata, Keiichi Maeda, Masayuki Yamanaka +38
We present optical observations of type Ia supernova (SN) 2019ein, starting at 2 days after the estimated explosion date. The spectra and the light curves show that SN 2019ein belo…
Morphology and dynamics of Venus's middle clouds with Akatsuki/IR1
J. Peralta, N. Iwagami, Sánchez-Lavega +8
The Venusian atmosphere is covered by clouds with super-rotating winds whose accelerating mechanism is still not well understood. The fastest winds, occurring at the cloud tops ($\…
Diagnosing the Clumpy Protoplanetary Disk of the UXor Type Young Star GM Cephei
P. C. Huang, W. P. Chen, M. Mugrauer +29
UX Orionis stars (UXors) are Herbig Ae/Be or T Tauri stars exhibiting sporadic occultation of stellar light by circumstellar dust. GM\,Cephei is such a UXor in the young (~M…
X-ray, Optical, and Near-infrared Monitoring of the New X-ray Transient MAXI J1820+070 in the Low/hard State
Megumi Shidatsu, Satoshi Nakahira, Satoshi Yamada +26
We report X-ray, optical, and near-infrared monitoring of the new X-ray transient MAXI J1820070 discovered with MAXI on 2018 March 11. Its X-ray intensity reached Crab…
Large Polarization Degree of Comet 2P/Encke Continuum Based on Spectropolarimetric Signals During Its 2017 Apparition
Y. G. Kwon, M. Ishiguro, Y. Shinnaka +16
Spectropolarimetry is a powerful technique for investigating the physical properties of gas and solid materials in cometary comae without mutual contamination, but there have been…