Variable Star Bulletin

          Each issue is available in PDF.

No.121 2023 Jul.       PDF
SDSS J183131.63+420220.2: AM CVn star showing ER UMa-type behavior and long standstill
                Taichi Kato

No.120 2023 Jul.       PDF
ASASSN-22ak: La Belle au bois dormant in a hydrogen-depleted dwarf nova?
                Taichi Kato, Franz-Josef Hambsch, Berto Monard and Rod Stubbings

No.119 2023 May       PDF
Long-lasting high state of the high-field polar AR UMa
                Taichi Kato

No.118 2023 May       PDF
Low state in the post-nova V1315 Aql
                Taichi Kato

No.117 2023 May       PDF
Double outbursts in V544 Her and ASASSN-19yt
                Taichi Kato

No.116 2023 May       PDF
The 2022 active state of the AM CVn star NSV 1440
                Taichi Kato,@Rod Stubbings

No.115 2023 Apr.       PDF supplementary data
Eclipse observations of V838 Her (Nova Her 1991) during nova eruption
                Taichi Kato

No.114 2023 Apr.       PDF
SDSS J094002.56+274942.0: an SU UMa star with an orbital period of3.92 hours and an apparently unevolved secondary
                Taichi Kato, Tonny Vanmunster

No.113 2023 Apr.
      PDF
MASTER OT J055845.55+391533.4: SU UMa star with a dip and long rebrightening
                Taichi Kato, Hiroshi Itoh, Tonny Vanmunster, Seiichiro Kiyota, Katsuaki Kubodera,Pavol A. Dubovsky, Igor Kudzej, Tomáš Medulka, Filipp D. Romanov and David J. Lane

No.112 2023 Apr.       PDF
CM Mic and other ER UMa stars showing standstills
                Taichi Kato and Naoto Kojiguchi

No.111 2023 Feb.       PDF
MGAB-V240: 23-min AM CVn star showing both 12-d supercycle and standstills
                Taichi Kato


No.110 2023 Feb.
      PDF
On the orbital period of the dwarf nova CW Mon
                Taichi Kato and Franz-Josef Hambsch

No.109 2023 Feb.       PDF
ASASSN-15cm: an SU UMa star with an orbital period of 5.0 hours
                Taichi Kato

No.108 2023 Feb.       PDF
Visual,CCD and DSLR minima of eclipsing binaries during 2022
               
Kazuo Nagai

No.107 2023 Feb.       PDF
Genuine standstill in the AM CVn star CR Boo
                Taichi Kato, Yutaka Maeda, Masayuki Moriyama

No.106 2023 Feb.       PDF
SU UMa-type supercycle in the IW And-type dwarf nova BO Cet above the period gap
                Taichi Kato

No.105 2023 Jan.       PDF
LS And: WZ Sge-type outburst first time since the 1971 discovery
                Taichi Kato

No.104 2023 Jan.       PDF
Very low state in PY Per in 2022
                Taichi Kato

No.103 2022 Oct.       PDF
The TESS light curves of three short period Algol-type systems; X Tri is a real pulsator
                Shin-ya Narusawa and Kazuo Nagai


No.102 2022 May      PDF

Analysis of TESS observations of V844 Her during the 2020 superoutburst
                Taichi Kato

No.101 2022 May      PDF

Negative superhumps in the eclipsing Z Cam + VY Scl star ES Dra
                Taichi Kato

No.100 2022 Apr.      PDF

Z Cam star PY Per in SU UMa state?
                Taichi Kato

No.99 2022 Apr.       PDF

Gaia19bxc: possible polar below the period minimum
                Taichi Kato

No.98 2022 Apr.       PDF

Romanov V48: unusual intermediate polar in the period gap
                Taichi Kato and Filipp D. Romanov

No.97 2022 Mar.       PDF

Gaia22ayj: outburst from a deeply eclipsing 9.36-min binary?
                Taichi Kato

No.96 2022 Mar.       PDF

WFI J161953.3+031909: eclipsing ER UMa-type and Z Cam-type starin the period gap
                Taichi Kato

No.95 2022 Mar.       PDF

V476 Cyg (Nova Cyg 1920) is currently a dwarf nova \ first such an object in the period gap?
                Taichi Kato

No.94 2022 Mar.       PDF

Long-lasting standstill and fading episode in the IW And star V507 Cyg
                Taichi Kato and Masayuki Moriyama

No.93 2022 Mar.       PDF

On the identity of Tsesevichfs gYY Drah
                Taichi Kato and Elena P. Pavlenko

No.92 2022 Feb.       PDF

Analysis of the IW And star ASAS J071404+7004.3
                Taichi Kato, Kiyoshi Kasai, Elena P. Pavlenko, Nikolaj V. Pit, Aleksei A. Sosnovskij,
                Hiroshi Itoh, Hidehiko Akazawa, Stephen M. Brincat, Leonid E. Keir, Sergei N. Udovichenko,
                Yusuke Tampo, Naoto Kojiguchi, Masaaki Shibata, Yasuyuki Wakamatsu, Tamás Tordai,
                Tonny Vanmunster and Charles Galdies


No.91 2022 Feb.       PDF

Visual, DSLR and CCD minima of eclipsing binaries during 2021
                Kazuo Nagai

No.90 2022 Feb.       PDF
Emerging ordinary superhumps as the standard candle for WZ Sge stars
                Taichi Kato

No.89 2022 Jan.       PDF
Evolution of short-period cataclysmic variables: implications from eclipse modeling and stage A superhump method (with New Yearfs gift)
                Taichi Kato

No.88 2021 Dec.       PDF
Orbital period of the IW And-type star ST Cha
                Taichi Kato

No.87 2021 Dec.       PDF
Study of the low-amplitude Z Cam star IX Vel
                Taichi Kato

No.86 2021 Nov.       PDF
A code for two-dimensional frequency analysis using the Least Absolute Shrinkage and Selection Operator (Lasso) for multidisciplinary use
                Taichi Kato

No.85 2021 Nov.
      PDF
Periodic modulations during a long outburst in V363 Lyr
                Taichi Kato

No.84 2021 Nov.
      PDF
ASASSN-19ax: SU UMa-type dwarf nova with a long superhump period and post-superoutburst rebrightenings
                Taichi Kato, Hiroshi Itoh, Seiichiro Kiyota, Tonny Vanmunster, Tamás Tordai,
                Yusuke Tampo, Naoto Kojiguchi, Masaaki Shibata, Junpei Ito, Roger D. Pickard, Sjoerd Dufoer

No.83 2021 Oct.       PDF
On the nature of embedded precursors in long outbursts of
SS Cyg stars as inferred from observations of the IW And star ST Cha
                Taichi Kato and Franz-Josef Hambsch

No.82 2021 Oct.       PDF
Algol-type system RZ Cas: Times of primary minima by different methods
                Shin-ya Narusawa and Kazuo Nagai

No.81 2021 Sep.       PDF

Orbital and spin periods of the candidate white dwarf pulsar
ASASSN-V J205543.90+240033.5
                Taichi Kato, Franz-Josef Hambsch, Elena P. Pavlenko, Aleksei A. Sosnovskij

No.80 2021 Aug.       PDF

ASASSN-V J205543.90+240033.5: another white dwarf pulsar?
                Taichi Kato

No.79 2021 Aug.       PDF Reviced on Nov.15, 2021
MP Gem: VY Scl-type star, finally
                Taichi Kato

No.78 2021 Jul.       PDF

MGAB-V859 and ZTF18abgjsdg: ER UMa-type dwarf novae showing standstills
                Taichi Kato and Naoto Kojiguchi


No.77 2021 Jul.
      PDF

ZTF J185139.81+171430.3 = ZTF18abnbzvx: the second white dwarf pulsar?
                Taichi Kato and Naoto Kojiguchi


No.76 2021 Jul.
      PDF

V606 Aql (Nova Aquilae 1899) is now a dwarf nova
                Taichi Kato and Naoto Kojiguchi


No.75 2021 Jul.
      PDF

On the superhumps and mass ratio of CzeV404
                Taichi Kato


No.74 2021 Jul.
      PDF


Optical Variability Correlated with X-ray Spectral Transition
in the Black-Hole Transient ASASSN-18ey = MAXI J1820+070
                Keito Niijima, Mariko Kimura, Yasuyuki Wakamatsu, Taichi Kato, Daisaku Nogami, Keisuke Isogai
                Naoto Kojiguchi, Ryuhei Ohnishi, Megumi Shidatsu, Geoffrey Stone, Franz-Josef Hambsch,
                Tam
́as Tordai, Michael Richmond, Tonny Vanmunster, Gordon Myers, Stephen M. Brincat,
                Pavol A. Dubovsky, Tomas Medulka, Igor Kudzej, Stefan Parimucha, Colin Littlefield,
                Berto Monard, Joseph Ulowetz, Elena P. Pavlenko, Oksana I. Antonyuk, Aleksei A. Sosnovskij,
                Aleksei V. Baklanov, Kirill A. Antoniuk, Nikolai V. Pit. Sergei P. Belan, Julia V. Babina,
                Aleksandr S. Sklyanov, Anna M. Zaostrozhnykh, Andrew V. Simon, Lewis M. Cook, Ian Miller,
                Hiroshi Itoh, Domenico Licchelli, Shawn Dvorak, Richard Sabo, Yenal 
Ögmen, Donn R. Starkey,
                Peter Nelson, Enrique de Miguel, Charles Galdies, Kenneth Menzies, Seiichiro Kiyota,
                Arto Oksanen, Roger D. Pickard, Alexandra M. Zubareva, Klaus Wenze and Denis Denisenko


No.73 2021 Feb.
      PDF

New Times of Minima of Algol type Systems XZ And, AB Cas and 
ƒÀ Per
                Shin-ya Narusawa and Hidehiko Akazawa

No.72 2021 Feb.       PDF

Multisite photometry of Algol-type binary system RZ Cas
                Shin-ya Narusawa, Hidehiko Akazawa, Kikuichi Arai, Mitugu Fujii, Fredy Doncel Invernizzi, Masayuki Ioroi, Yoshiharu Ito, Koichi Morikawa and Nobuo Ohkura

No.71 2021 Feb.       PDF

The flat bottom of the primary minimum of Algol-type system BR Cyg
                Shin-ya Narusawa

No.70 2021 Feb.       PDF

Reassess RZ Cas light curves at primary minima during 1995-1996
                Shin-ya Narusawa, Kikuichi Arai, Mitugu Fijii, Kazuo Nagai and Takeshi Yasuda

No.69 2021 Feb.       PDF

Visual, DSLR and CCD minima of eclipsing binaries during 2020
                Kazuo Nagai

No.68 2020 Dec.       PDF

Photometric observations of nine Algol systems
                Shin-ya Narusawa and Yasuhisa Nakamura

No.67 2020 Feb.       PDF

Visual, DSLR and CCD minima of eclipsing binaries during 2019
                Kazuo Nagai

No.66 2019 Jan.       PDF

Visual, DSLR and CCD minima of eclipsing binaries during 2018
                Kazuo Nagai

No.65 2018 Oct.       PDF

CCD and DSLR maxima of RR Lyrase stars in 2016 and 2017
-Joint publication: GEOS circular RR 58-
                
Kenji Hirosawa and J.F. Le Borgne

No.64 2018 Jan.       PDF

Visual, DSLR and CCD minima of eclipsing binaries during 2017
                Kazuo Nagai

No.63 2017 Feb.       PDF

Visual, DSLR and CCD minima of eclipsing binaries during 2016
                Kazuo Nagai

No.62 2016 Feb.       PDF

CCD and DSLR maxima of RR Lyrase stars in 2015
                
Kenji Hirosawa

No.61 2016 Feb.       PDF

Visual, DSLR and CCD minima of eclipsing binaries during 2015
                Kazuo Nagai

No.60 2016 Jan.       PDF

New light elements for four Eclipsing Binaries, CW Ori, OT Lac, CR Per and V610 Cyg
                Kiyoshi Kasai and Kazuo Nagai

No.59 2015 Jan.       PDF

Visual, DSLR and CCD minima of eclipsing binaries during 2014
                Kazuo Nagai

No.58 2015 Jan.       PDF

CCD and DSLR maxima of RR Lyrase stars in 2014
                
Kenji Hirosawa

No.57 2014 Feb.       PDF

CCD and DSLR maxima of RR Lyrase stars in 2013
                
Kenji Hirosawa

No.56 2014 Feb.       PDF

Visual and CCD minima of eclipsing binaries during 2013
                Kazuo Nagai

Errata for No.55 (2013 Jul.)       PDF

No.55 2013 Feb.       PDF

Visual and CCD minima of eclipsing binaries during 2012
                Kazuo Nagai


No.54 2013 Feb.       PDF

CCD and DSLR maxima of RR Lyrase stars in 2012
                Kenji Hirosawa

No.53 2012 Jan.       PDF

Visual and CCD minima of eclipsing binaries during 2011
                Kazuo Nagai


No.52 2012 Jan.       PDF (Rev. 1.1  2012 Jan. 24. Some duplicated entries were deleted.)

Visual and CCD maxima of RR Lyrase stars in 2003 -2011
                Kenji Hirosawa

No.51 2011 Feb.       PDF

Visual and CCD minima of eclipsing binaries during 2010
                Kazuo Nagai


No.50 2010 Feb.       PDF

Visual and CCD minima of eclipsing binaries during 2009
                Kazuo Nagai

No.49 2009 Apr.       PDF

Rebrightening Phenomenon in Classical Novae
                Taichi kato, Kazuhiro Nakajima, Hiroyuki Maehara and Seiichiro Kiyota

No.48 2009 Apr.       PDF

Visual and CCD minima of eclipsing binaries during 2008
                Kazuo Nagai

No.47 2008 Oct.       PDF

Visual and CCD minima of eclipsing binaries during 1900-1999
                Kazuo Nagai


Errata for No.44 (2008 Feb.)       html

No.46 2008 Feb.       PDF

Visual and CCD minima of eclipsing binaries during 2007
                Kazuo Nagai

Errata for No.39-44 (2007 Feb.)       html

No.45 2007 Feb.       PDF

Visual and CCD minima of eclipsing binaries during 2006
                Kazuo Nagai

No.44 2006 Feb.       PDF

Visual and CCD minima of eclipsing binaries during 2005
                Kazuo Nagai

No.43 2005 Feb.       PDF

Visual and CCD minima of eclipsing binaries during 2004
                Kazuo Nagai

No.42 2004 Feb.       PDF

Visual and CCD minima of eclipsing binaries during 2003
                Kazuo Nagai

No.41 2003 Oct.       PDF

First period determination of V1899 Sgr
                 Taichi Kato

UW Aqr is a variable star
                 Taichi Kato

ZZ Aqr is a semiregular variable resembling Z UMa
                 Taichi Kato

No.40 2003 Feb.       PDF

Visual and CCD minima of eclipsing binaries during 2002
                Kazuo Nagai

No.39 2002 Jan.       PDF

Remarkable yellow supergiant variable TmzV429
                Taichi Kato and Kesao Takamizawa

Visual and CCD minima of eclipsing binaries during 2001
                Kazuo Nagai

No.38 2001 Jan.       PDF

The overall lightcurve of the second historical decline of BZ Cam
                Tsutomu Watanabe

Visual and CCD minima of eclipsing binaries during 2000
                Kazuo Nagai

No.37 2000 Mar.       PDF

Detection of the second historical decline of BZ Cam
                Tsutomu Watanabe

Visual and CCD minima of eclipsing binaries during 1999
                Kazuo Nagai

No.35-36 2000 Jan.    PDF

Medium-term variability of FY Per
                Tsutomu Watanabe
                Hiroyuki Maehara

Eclipse period of FN Sgr
                Tsutomu Watanabe

Period revision of ES Del
                 Tsutomu Watanabe

No.34 1999 Sep.       PDF

Outburst of BF Eri
                 Tsutomu Watanabe

Outburst of TmzV34 (= RXJ0915.8+0900)
                 Tsutomu Watanabe

Outburst of Goranskij's variable near GM Sgr
                 Tsutomu Watanabe

Detection of the second historical decline of VY-Scl type variable LQ Peg
                 Tsutomu Watanabe

No.33 1999 Apr.        PDF

Visual and CCD minima of eclipsing binaries during 1998
                 Kazuo Nagai

Detection of an Eclipse during the 1987 Outburst of U Sco
                 Taichi Kato

No.32 1998 Oct.        PDF

Outburst of RX J0575.0+6306
                 Tsutomu Watanabe

Light Curve of SBS1017+533
                 Tsutomu Watanabe

No.30-31 1998 Aug.     PDF

Outburst of Possible Eclipsing Symbiotic Variable AS 289
                 Kesao Takamizawa
                 Minoru Wakuda
                 Taichi Kato

22 new variable stars discoverd from patrol films (new variable stars series III)
                 Kesao Takamizawa
@

No.28-29 1998 Apr.      PDF fig.1

12 new variable stars discoverd from patrol films (new variable stars series II)
                 Kesao Takamizawa

Visual and CCD minima of eclipsing binaries during 1997
                 Kazuo Nagai

No.26-27 1997 Dec.      PDF 

9 NEW VARIABLE STARS DISCOVERED FROM PATROL FILMS
                 Kesao Takamizawa

No.25 1997 Dec.         PDF

Least-Squares Strategy for Analyzing Pogson's Step Method
                 Taichi Kato

Reanalysis of Photographic Observations of CY UMa in 1988
                 Taichi Kato

Prediscovery Photographic Observation of V4334 Sgr (Sakurai's Object)
                 Kesao Takamizawa

No.24 1997 Dec.          PDF

Resumption of Pulsation of RU Cam around 1970: Evidence from the VSOLJ Database
                 Minoru Sato

Reanalysis of Ichinohe's Observations of RU Cam
                 Taichi Kato

No.23 1997 Oct.           PDF

Visual and CCD minima of eclipsing binaries during 1995-96

No.22 1996 Sep.          PDF

CCD Observation of nova Sgr 1994 no.2
                 Seiichiro Kiyota


CCD Observation of nova Aql 1995
                 Seiichiro Kiyota


CCD Observations of symbiotic nova discovered by M. Wakuda during 1994-1995
                 Seiichiro Kiyota

No.21 1995 Dec.          PDF

Possible new MIRA type variable in Sagittarius
                Keiichiro Minoda

Reviced orbital period of IP Peg and possible existence of superhump-like periodicity during outbursts
                T. Kato, M. Iida, S. fujino, M. Yamada, N. makiguchi, K. hirosawa, M. Ishii

No.20 1995 Aug.          PDF

Photographic Observation of NSV12245, 12376, 12656, 12883 & 13204 by Prof. Huruhata
                Seiichi Sakuma

No.19 1994 Oct.          PDF

Photographic observations of a symbiotic nova 1994 in Sagittarius before discovery
                                Minoru Wakuda, MInoru Yamamoto and Yukio Sakurai

Visual observation of PG 043+521: A new dwafr nova in the Palomer Green Survey
                                Makoto Iida

No.18 1993 May           PDF

Summary of the database of VSOLJ. Part.3 (Ser-Vul, NSV star, Super nova & Var.star in Messier object)
                Seiichi Sakuma

No.17 1993 May           PDF

Summary of the database of VSOLJ. Part.2 (Gem-Sct)
                                Seiichi Sakuma

No.16 1993 May           PDF

Summary of the database of VSOLJ. Part.1 (And-For)
                Seiichi Sakuma

No.15 1992 Apr.         
PDF

Seach for Mira variables from IRAS Catalogue of Point Sorce
                Minari Iida

No.14 1992 Apr.          PDF

A possible new Mira type varoable in Delphinus
               Yukio Sakurai

Some new variables in Monoceros
               Minoru Wakuda

No.13 1991 May           PDF

Photometry of 32 Cyg and Gamma Per around 1990 Eclipse
                              T. Izutu, K. Kosaka, M.Magome and T. Yamasaki

Visual obervations of NSV1020, NSV9887 and NSV14469
               Makoto Iida

Faint state of PG0911-066
                              Taichi Kato

No.12 1990 Jul.          PDF

Late Prof. M. Huruhata's photographic observation of variable starts.
                              S. Sakuma

No.11 1990 Jun.          PDF

Revised elements for EH Canis Majoris
                              M. Koshiro

Possible cataclysmic variable in Cassiopea
                               M. Iida

Reviced elements for AD Draconis
               S. Sakuma

No.10 1989 Jun.          PDF

AW Gem: A new SU Uma star
               S. Fujino and M. Nakai, M. Iida, M. Moriyama, N. Makiguchi and T. Kato

Recent behavior of CY UMa
                              M. Watababe, K.Hirosawa, T. Kato and H. Narumi

No.9  1989 Apr.          PDF

Detection of superhumps in dwarf nova AQ Eridani
                              T. Kato, S. Fujino and M. Iida

A new ephemeris of AK Hya
               Kazuaki Gimi snd Msami Koshiro

Observation of V362Cep
               S. Kiyota

Prof. M. Huruhata in Memorium

No.8  1988 Nov.          PDF

Observation of Wakuda's new MIra type variable in Canis Major
                               M. Yasuki

Suspected variable star near Z Mon by Dr. Ichinohe
               S. Sakuma

No.7  1988 Aug.          PDF

Photographic obervation of V718 tau
               M. Hurhata

No.6  1988 Apr.          PDF

Recent ephemeris of algol
                               M. Kanai

Periodicity of GP CMa
               M. Huruhata snd M. Wakuda

No.5  1988 Feb.          PDF

Photographic observations of eclipsing of AS 338
               M. Wakuda

CY Ursae Majoris - A new SU UMa system with ultra short orbial period
               T. Kato, S. fujino, M. iida, N. makuguchi and M. Koshiro

A possible new MIra type variable in Taurus
               M. Huruhata

No.4  1987 Dec.         
PDF

Some new In variables in Orion nebula
               M. Huruhata

Observations of eclipse IP Pegasi
               M. Koshiro and S. Fujino

Viaual observations of minima of IP pegasi
               M. Iida

Visual oberrvations of VZ Cam
               S. Sakuma

No.3  1987 Oct.          PDF

Photographic and visual observations of eclipses of EX Hydrae
               S. Fujino,  K. Fujino, M. Iida and T. Kato

Determination of superhump-period of T. Leonis
               T. Kato and S. Fujino

Visual observations of NSV13991
               K. Gomi

No.2  1987 Aug.          PDF

Observations of the eclipse of IP Peg in 1985
               S. Akita, S. Fujino and T. Kato

Obervations of eclipse of IP Peg in 1986
               S. Fujino

A New red variable in Cygnus
                              M. Huruhata

Periodicity of V1152 Cygni
               M. Huruhata

No.1  1987 Jun.          PDF

Photographic observations of KR Aur in 1985/1986
               S. Fujino, M. Huruhata, T. Saito amd M. Wakuda

Perio shortning of SS CMa
               M. Koshiro

Visual obervations of PW Vul
                              M. Watanabe

VSOLJ
 

Return