340 citations · 1.9k across the 38 of their papers we have counts for
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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…
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…
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…
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…
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…
Superoutburst of SDSS J090221.35+381941.9: First Measurement of Mass Ratio in an AM CVn-Type Object using Growing Superhumps
Taichi Kato, Tomohito Ohshima, Denis Denisenko +36
We report on a superoutburst of the AM CVn-type object SDSS J090221.35+381941.9 [J0902; orbital period 0.03355(6) d] in 2014 March-April. The entire outburst consisted of a precurs…
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. VI: The Sixth Year (2013-2014)
Taichi Kato, Pavol A. Dubovsky, Igor Kudzej +83
Continuing the project described by Kato et al. (2009, PASJ, 61, S395, arXiv:0905.1757), we collected times of superhump maxima for 56 SU UMa-type dwarf novae mainly observed durin…
Study of Negative and Positive Superhumps in ER Ursae Majoris
Tomohito Ohshima, Taichi Kato, Elena Pavlenko +45
We carried out the photometric observations of the SU UMa-type dwarf nova ER UMa during 2011 and 2012, which showed the existence of persistent negative superhumps even during the…
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. V: The Fifth Year (2012-2013)
Taichi Kato, Franz-Josef Hambsch, Hiroyuki Maehara +84
Continuing the project described by Kato et al. (2009a, arXiv:0905.1757), we collected times of superhump maxima for SU UMa-type dwarf novae mainly observed during the 2012-2013 se…
WZ Sge-type dwarf novae with multiple rebrightenings: MASTER OT J211258.65+242145.4 and MASTER OT J203749.39+552210.3
Chikako Nakata, Tomohito Ohshima, Taichi Kato +25
We report on photometric observations of WZ Sge-type dwarf novae, MASTER OT J211258.65+242145.4 and MASTER OT J203749.39+552210.3 which underwent outbursts in 2012. Early superhump…
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. IV: The Fourth Year (2011-2012)
Taichi Kato, Franz-Josef Hambsch, Hiroyuki Maehara +85
Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we studied 86 SU UMa-type dwarf novae. We confirmed the general trends such as the relation between period…
Discovery of Negative Superhumps during a Superoutburst of January 2011 in ER Ursae Majoris
Tomohito Ohshima, Taichi Kato, Elena P. Pavlenko +19
We report on a discovery of "negative" superhumps during the 2011 January superoutburst of ER UMa. During the superoutburst which started on 2011 January 16, we detected negative s…
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. III: The Third Year (2010--2011)
Taichi Kato, Hiroyuki Maehara, Ian Miller +75
Continuing the project described by Kato et al. (2009, PASJ 61, S395, arXiv:0905.1757), we collected times of superhump maxima for 51 SU UMa-type dwarf novae mainly observed during…