69 citations · 297 across the 16 of their papers we have counts for
16 papers
The age and metallicity dependence of the near-infrared absolute magnitude and colour of red clump stars
Hiroki Onozato, Yoshifusa Ita, Yoshikazu Nakada
Understanding the age and metallicity dependence of the absolute magnitude and colour of red clump (RC) stars is crucial for validating the accuracy of stellar evolution models and…
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 , , $…
The Thirty Millimeter Telescope
Yoshifusa Ita, Takashi Ichikawa, Hironori Tsutsui +11
A near-infrared telescope with an effective aperture diameter of thirty millimeters has been developed. The primary objective of the development is to observe northern bright stars…
A Very Metal-poor RR Lyrae Star with a Disk Orbit Found in the Solar Neighborhood
Noriyuki Matsunaga, Akinori Itane, Kohei Hattori +28
Metal-deficient stars are important tracers for understanding the early formation of the Galaxy. Recent large-scale surveys with both photometric and spectroscopic data have report…
J-GEM optical and near-infrared follow-up of gravitational wave events during LIGO's and Virgo's third observing run
Mahito Sasada, Yousuke Utsumi, Ryosuke Itoh +68
The Laser Interferometer Gravitational-wave Observatory Scientific Collaboration and Virgo Collaboration (LVC) sent out 56 gravitational-wave (GW) notices during the third observin…
Long-Term Near-Infrared Brightening of Non-Variable OH/IR Stars
Takafumi Kamizuka, Yoshikazu Nakada, Kenshi Yanagisawa +8
Non-variable OH/IR stars are thought to have just left the asymptotic giant branch (AGB) phase. In this conventional picture, they must still show strong circumstellar extinction c…
Optical and X-ray observations of stellar flares on an active M dwarf AD Leonis with Seimei Telescope, SCAT, NICER and OISTER
Kosuke Namekata, Hiroyuki Maehara, Ryo Sasaki +24
We report multi-wavelength monitoring observations of an M-dwarf flare star AD Leonis with Seimei Telescope (6150--7930 Å), SCAT (Spectroscopic Chuo-university Astronomical Telesco…
An optical search for transients lasting a few seconds
Michael W. Richmond, Masaomi Tanaka, Tomoki Morokuma +37
Using a prototype of the Tomo-e Gozen wide-field CMOS mosaic camera, we acquire wide-field optical images at a cadence of 2 Hz and search them for transient sources of duration 1.5…
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…
The Age and Metallicity Dependence of the Near-Infrared Magnitudes of Red Clump Stars
Hiroki Onozato, Yoshifusa Ita, Yoshikazu Nakada +1
Red clump (RC) stars are widely used as an excellent standard candle. To make them even better, it is important to know the dependence of their absolute magnitudes on age and metal…
Discovery of carbon-rich Miras in the Galactic bulge
Noriyuki Matsunaga, John W. Menzies, Michael W. Feast +4
Only one carbon-rich (C-rich, hereinafter) Mira variable has so far been suggested as a member of the Galactic bulge and this is in a symbiotic system. Here we describe a method fo…
Broad-Lined Supernova 2016coi with Helium Envelope
Masayuki Yamanaka, Tatsuya Nakaoka, Masaomi Tanaka +38
We present the early-phase spectra and the light curves of the broad-lined supernova (SN) 2016coi from to days after the estimated explosion date. This SN was initially…
V5852 Sgr: An Unusual Nova Possibly Associated with the Sagittarius Stream
E. Aydi, P. Mróz, P. A. Whitelock +16
We report spectroscopic and photometric follow-up of the peculiar nova V5852~Sgr (discovered as OGLE-2015-NOVA-01), which exhibits a combination of features from different nova cla…
The K2-ESPRINT Project III: A Close-in Super-Earth around a Metal-rich Mid-M Dwarf
Teruyuki Hirano, Akihiko Fukui, Andrew W. Mann +18
We validate a planet on a close-in orbit ( days) around K2-28 (EPIC 206318379), a metal-rich M4-type dwarf in the Campaign 3 fiel…
A Study of Mid-Infrared Sources that Dramatically Brightened
Hiroki Onozato, Yoshifusa Ita, Kenji Ono +5
We present results of near-infrared photometric and spectroscopic observations of mid-infrared (MIR) sources that dramatically brightened. Using IRAS, AKARI, and WISE point source…
Multi-band, Multi-epoch Observations of the Transiting Warm Jupiter WASP-80b
Akihiko Fukui, Yui Kawashima, Masahiro Ikoma +22
WASP-80b is a warm Jupiter transiting a bright late-K/early-M dwarf, providing a good opportunity to extend the atmospheric study of hot Jupiters toward the lower temperature regim…