340 citations · 1.9k across the 38 of their papers we have counts for
38 papers
EPISODE II: Variability in the CO and HO rovibrational absorption lines in a periodically variable protostar EC 53
Seokho Lee, Jeong-Eun Lee, Chul-Hwan Kim +19
We present two-epoch JWST NIRSpec and MIRI observations of the young protostar EC 53 (V371 Ser), a periodically variable source with well-characterized quiescent and burst phases.…
Discovery of multi-temperature coronal mass ejection signatures from a young solar analogue
Kosuke Namekata, Kevin France, Jongchul Chae +14
Coronal mass ejections (CMEs) on the early Sun may have profoundly influenced the planetary atmospheres of early Solar System planets. Flaring young solar analogues serve as excell…
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…
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…
Secular Variation in the Interval of Outbursts in Z Cam-type Dwarf Novae
Tomohito Ohshima
The secular variation in the interval of outbursts in the following six Z Cam-type dwarf novae (including the subtype IW And-type) is investigated: Z Cam, RX And, AH Her, HL CMa, S…
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…
Intermediate Luminosity Type Iax SN 2019muj With Narrow Absorption Lines: Long-Lasting Radiation Associated With a Possible Bound Remnant Predicted by the Weak Deflagration Model
Miho Kawabata, Keiichi Maeda, Masayuki Yamanaka +23
We present comprehensive spectroscopic and photometric analyses of the intermediate luminosity Type Iax supernova (SN Iax) 2019muj based on multi-band datasets observed through the…
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…
Time-resolved spectroscopy and photometry of an M dwarf flare star YZ Canis Minoris with OISTER and TESS: Blue asymmetry in H line during the non-white light flare
Hiroyuki Maehara, Yuta Notsu, Kousuke Namekata +15
In this paper, we present the results from spectroscopic and photometric observations of the M-type flare star YZ CMi in the framework of the Optical and Infrared Synergetic Telesc…
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. X: The Tenth Year (2017)
Taichi Kato, Keisuke Isogai, Yasuyuki Wakamatsu +67
Continuing the project described by Kato et al. (2009, PASJ, 61, S395, arXiv/0905.1757), we collected times of superhump maxima for 102 SU UMa-type dwarf novae observed mainly duri…
Third Nearest WZ Sge-Type Dwarf Nova candidate ASASSN-14dx Classified on the Basis of Gaia Data Release 2
Keisuke Isogai, Taichi Kato, Akira Imada +8
ASASSN-14dx showed an extraordinary outburst whose features are the small outburst amplitude (~ 2.3 mag) and long duration (> 4 years). Because we found a long observational gap of…
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…
Kilonova from post-merger ejecta as an optical and near-infrared counterpart of GW170817
Masaomi Tanaka, Yousuke Utsumi, Paolo A. Mazzali +42
Recent detection of gravitational waves from a neutron star (NS) merger event GW170817 and identification of an electromagnetic counterpart provide a unique opportunity to study th…
J-GEM observations of an electromagnetic counterpart to the neutron star merger GW170817
Yousuke Utsumi, Masaomi Tanaka, Nozomu Tominaga +57
The first detected gravitational wave from a neutron star merger was GW170817. In this study, we present J-GEM follow-up observations of SSS17a, an electromagnetic counterpart of G…
OISTER Optical and Near-Infrared Monitoring Observations of a Peculiar Radio-Loud Active Galactic Nucleus SDSS J110006.07+442144.3
Tomoki Morokuma, Masaomi Tanaka, Yasuyuki T. Tanaka +80
We present monitoring campaign observations at optical and near-infrared (NIR) wavelengths for a radio-loud active galactic nucleus (AGN) at z=0.840, SDSS~J110006.07+442144.3 (here…
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. IX: The Ninth Year (2016-2017)
Taichi Kato, Keisuke Isogai, Franz-Josef Hambsch +76
Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 127 SU UMa-type dwarf novae observed mainly during the 2016--201…
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. VIII: The Eighth Year (2015-2016)
Taichi Kato, Franz-Josef Hambsch, Berto Monard +75
Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 128 SU UMa-type dwarf novae observed mainly during the 2015-2016…
Superoutburst of CR Bootis: Estimation of Mass Ratio of a typical AM CVn star by Stage A Superhumps
Keisuke Isogai, Taichi Kato, Tomohito Ohshima +31
We report on two superoutbursts of the AM CVn-type object CR Boo in 2014 April--March and 2015 May--June. A precursor outburst acompanied both of these superoutbursts. During the r…
No Evidence of Intrinsic Optical/Near-Infrared Linear Polarization for V404 Cygni During its Bright Outburst in 2015: Broadband Modeling and Constraint on Jet Parameters
Y. T. Tanaka, R. Itoh, M. Uemura +39
We present simultaneous optical and near-infrared (NIR) polarimetric results for the black hole binary V404 Cygni spanning the duration of its 7-day long optically-brightest phase…
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. VII: The Seventh Year (2014-2015)
Taichi Kato, Franz-Josef Hambsch, Pavol A. Dubovsky +89
Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 102 SU UMa-type dwarf novae observed mainly during the 2014-2015…
OT J075418.7+381225 and OT J230425.8+062546: Promising Candidates for the Period Bouncer
Chikako Nakata, Taichi Kato, Daisaku Nogami +15
We report on photometric observations of two dwarf novae, OT J075418.7+381225 and OT J230425.8+062546, which underwent superoutburst in 2013 (OT J075418) and in 2011 (OT J230425).…
Dwarf Nova EZ Lyncis Second Visit to Instability Strip
Elena Pavlenko, Taichi Kato, Aleksei A. Sosnovskij +5
The analysis of 14 periodograms of EZ Lyn for the data spaced over 565 d in 2012--2014 (2-3.5 yr after 2010 outburst) yielded the existence of the stable signals around 100 c/d and…
NY Serpentis: SU UMa-Type Nova in the Period Gap with Diversity of Normal Outbursts
Elena P. Pavlenko, Taichi Kato, Oksana I. Antonyuk +16
We present photometric study of NY Ser, an in-the-gap SU UMa-type nova, in 2002 and 2013. We determined the duration of the superoutburst and the mean superhump period to be 18 d a…