Search Publications
Smart Kanata: A framework for autonomous decision-making in rapid follow-up observations of cataclysmic variables
Maehara, Hiroyuki; Nogami, Daisaku; Uemura, Makoto +11 more
Studying the early stages of transient events provides crucial information about the fundamental physical processes in cataclysmic variables (CVs). However, determining an appropriate observation mode immediately after the discovery of a new transient presents challenges due to significant uncertainties regarding its nature. We developed a framewo…
ALMA 2D super-resolution imaging of Taurus-Auriga protoplanetary disks: Probing statistical properties of disk substructures
Tamura, Motohide; Yamaguchi, Masayuki; Nomura, Hideko +6 more
In the past decade, ALMA observations of protoplanetary disks revealed various substructures including gaps and rings. Their origin of substructures may be probed through statistical studies of their physical properties. We present the analyses of archival ALMA Band 6 continuum data of 43 disks (39 Class II and four Herbig Ae) in the Taurus-Auriga…
JASMINE: Near-infrared astrometry and time-series photometry science
Ouchi, Masami; Isobe, Naoki; Notsu, Yuta +86 more
The Japan Astrometry Satellite Mission for INfrared Exploration (JASMINE) is a planned M-class science space mission by the Institute of Space and Astronautical Science, the Japan Aerospace Exploration Agency. JASMINE has two main science goals. One is Galactic archaeology with a Galactic Center survey, which aims to reveal the Milky Way's central…
The Milky Way tomography with Subaru Hyper Suprime-Cam. I. Halo substructures
Komiyama, Yutaka; Takada, Masahiro; Tanaka, Masayuki +7 more
We analyze the photometric data in the Wide layer of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) over ~1200 deg2 to uncover new halo substructures beyond the distance, D⊙ ~ 30 kpc, from the Sun. For this purpose, we develop an isochrone filter for an old, metal-poor stellar system to extract the faint main-sequen…
New insights on the dynamics of satellite galaxies: Effects of the figure rotation of a host galaxy
Chiba, Masashi; Sato, Genta
We investigate a mechanism to form and keep a planar spatial distribution of satellite galaxies in the Milky Way (MW), which is called the satellite plane. It has been pointed out that the ΛCDM cosmological model hardly explains the existence of such a satellite plane, so it is regarded as one of the serious problems in the current cosmology. We h…
MASTER OT J030227.28+191754.5: An unprecedentedly energetic dwarf nova outburst
Schramm, Malte; Maehara, Hiroyuki; Nogami, Daisaku +60 more
We present a detailed study of the MASTER OT J030227.28
Diffraction modelling of a 2023 March 5 stellar occultation by subkilometer-sized asteroid (98943) 2001 CC21
Arimatsu, Ko; Hirabayashi, Masatoshi; Akitaya, Hiroshi +31 more
We present an analysis of a stellar occultation event caused by a near-Earth asteroid (98943) 2001 CC21, an upcoming flyby target in the Hayabusa2 extended mission, on 2023 March 5. To determine the asteroid's shape from diffraction-affected light curves accurately, we developed a novel data-reduction technique named the Diffracted Occultation's U…
The extended halo and tidal tails of the old open cluster NGC 2112
Gao, Xinhua; Zhu, Chengyu
This paper investigates the spatial structure and tidal tails of the nearby (
A comprehensive study of an oscillating eclipsing Algol: Y Camelopardalis
Kahraman Aliçavuş, Filiz; Çelik, Eda
Y Camelopardalis (Y Cam) is classified as one of the oscillating eclipsing Algol (oEA) systems, which feature a $\delta$ Scuti-type pulsating component alongside mass transfer phenomena. oEA systems are invaluable for probing the evolutionary processes and internal structures of binary components, offering insights through their binary variations …
MK-like spectral classification for hot subdwarf stars with LAMOST spectra
Lei, Zhenxin; Zou, Xuan
An MK-like spectral classification has been conducted for 1224 hot subdwarf stars with LAMOST DR9 low-resolution spectra. The whole sample was divided into four categories according to the spectral line characteristics: He-normal, He-weak, He-strong C, and He-strong. Each selected spectrum was assigned a spectral class, a luminosity class, and a h…