159 citations · 564 across the 12 of their papers we have counts for
12 papers
MASTER OT J030227.28+191754.5: an unprecedentedly energetic dwarf nova outburst
Yusuke Tampo, Taichi Kato, Keisuke Isogai +60
We present a detailed study of the MASTER OT J030227.28+191754.5 outburst in 2021-2022, reaching an amplitude of 10.2 mag and a duration of 60 d. The detections of (1) the double-p…
Discovery of a Long-Duration Superflare on a Young Solar-Type Star EK Draconis with Nearly Similar Time Evolution for H and White-Light Emissions
Kosuke Namekata, Hiroyuki Maehara, Satoshi Honda +17
Young solar-type stars are known to show frequent "superflares", which may severely influence the habitable worlds on young planets via intense radiations and coronal mass ejection…
Probable detection of an eruptive filament from a superflare on a solar-type star
Kosuke Namekata, Hiroyuki Maehara, Satoshi Honda +20
Solar flares are often accompanied by filament/prominence eruptions ( K and cm), sometimes leading to coronal mass ejections (CMEs) that direct…
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…
ASASSN-18aan: An Eclipsing SU UMa-type Cataclysmic Variable with a 3.6-hour Orbital Period and a Late G-type Secondary Star
Yasuyuki Wakamatsu, John R. Thorstensen, Naoto Kojiguchi +41
We report photometric and spectroscopic observations of the eclipsing SU UMa-type dwarf nova ASASSN-18aan. We observed the 2018 superoutburst with 2.3 mag brightening and found the…
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…
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…
New constraint on the atmosphere of (50000) Quaoar from a stellar occultation
Ko Arimatsu, Ryou Ohsawa, George L. Hashimoto +35
We report observations of a stellar occultation by the classical Kuiper belt object (50000) Quaoar occurred on 28 June 2019. A single-chord high-cadence (2 Hz) photometry dataset w…
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 ASTRO-H Mission
Tadayuki Takahashi, Kazuhisa Mitsuda, Richard Kelley +174
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will…
Suzaku Observation of the Metallicity Distribution in the Elliptical Galaxy NGC 4636
Katsuhiro Hayashi, Yasushi Fukazawa, Miyako Tozuka +4
NGC 4636, an X-ray bright elliptical galaxy, was observed for 70 ks with Suzaku. The low background and good energy resolution of the XIS enable us to estimate the foreground Galac…
Suzaku observation of the metallicity distribution in the intracluster medium of the Fornax cluster
Kyoko Matsushita, Yasushi Fukazawa, John P. Hughes +10
The metallicity distribution in the Fornax cluster was studied with the XIS instrument onboard the Suzaku satellite. K-shell lines of O and Mg were resolved clearly, and the abunda…