PAGE i S S C Y G N I L I G H T C U R V E S 1 9 9 1 - 1 9 9 5 AAVSO MONOGRAPH 1 SUPPLEMENT 2 This monograph is dedicated to Edward A. Halbach in recognition of his enthusiasm for and dedication to variable star observing and his support of the goals of the Association. Prepared by Janet A. Mattei Elizabeth O. Waagen E. Grant Foster Funds for preparation and publication provided by Edward A. Halbach Clinton B. Ford Additional funds provided by AAVSO Members International Astronomical Union (IAU) ----------------------------------------------------------------------------- PAGE ii ISBN 1-878174-14-2 COPYRIGHT 1996 by the American Association of Variable Star Observers 25 Birch Street Cambridge, Massachusetts 02138 USA All rights reserved. All commercial use of any part of this book requires the written permission of the AAVSO. All non-commercial use by individuals and educators is granted without restriction. ---------------------------------------------------------------------------- PAGE iii TABLE OF CONTENTS Introduction v Observers of SS Cygni vii Information on SS Cygni x Key to Symbols x Light Curves of SS Cygni, 1991 - 1995 1 ----------------------------------------------------------------------------- PAGE iv is blank ----------------------------------------------------------------------------- PAGE v SS CYGNI LIGHT CURVES, 1991 - 1995 Introduction AAVSO long-term light curves of variable stars contain crucial information that has a significant bearing on many outstanding questions in astrophysics. These light curves define the behavior of variable stars and provide basic sets of observations for multiwavelength data correlation, data analysis, and for checking theories and matching models. The monograph format enables us to present long-term variable star behavior, with each Monograph containing 20 or more years of computer-generated light curves on one star. Each Supplement to a Monograph continues the light curves of the same star, bringing them more up-to-date. SS Cygni Light Curves, 1991 - 1995 AAVSO Monograph 1, Supplement 2, contains light curves of SS Cygni from 1991 through 1995 (JD 2448258 - 2450083). Pages 1 through 10 contain computer-generated light curves with each dot representing one observation. Observations are plotted Julian date versus magnitude, and the start of each year (January 1) is indicated along the upper axis. A scaled grid is provided to assist in determining the exact date and magnitude of any data point. Factual information on SS Cygni and a Key to Symbols are given on page x. Earlier observations of SS Cygni have been published in AAVSO Monograph 1, SS Cygni Light Curves 1896 - 1985 and AAVSO Monograph 1, Supplement 1, SS Cygni Light Curves 1985 - 1990. The observations in AAVSO Monograph 1, Supplement 2, are the contributions of AAVSO members or observers in the United States and abroad. 426 observers have contributed 30,996 observations to these light curves. The names and observer codes of these observers are given on pages vii through ix. Organizations whose members have contributed observations to the AAVSO either individually or through their organization are listed on page ix. In preparing the data for publication, each observation was evaluated for accuracy by my senior technical assistant Elizabeth O. Waagen, and by me. Software used in evaluating and plotting the observations was developed by my technical assistant E. Grant Foster. The observations from 1991 through 1995 included in this supplement have been preserved on compact disc, cartridge, and printout. Electronic, diskette, or printout copies of observations for further analysis may be obtained by writing or sending email to the AAVSO Director at aavso@aavso.org. The data may also be retrieved for personal use (not for publication or distribution) from the AAVSO's ftp site: ftp.aavso.org (198.116.78.2) in /pub/monographs, or its home page: http://www.aavso.org. Acknowledgements We dedicate AAVSO Monograph 1, Supplement 2, to Edward A. Halbach. Ed is a longtime member and an enthusiastic and dedicated variable star observer, and has contributed generously towards the preparation of AAVSO monographs and supplements. We extend our sincere thanks to him. We remember with special thanks Clinton B. Ford for his very generous contribution for the preparation of this and subsequent monographs and monograph supplements. Our sincere thanks go to AAVSO members and friends for their contributions v ----------------------------------------------------------------------------- PAGE vi to prepare these monographs and monograph supplements. We thank the International Astronomical Union (IAU) for their support of our monograph series and for the grant provided to the AAVSO to publish this and other monographs and monograph supplements. We acknowledge with thanks the computer support of the Smithsonian Astrophysical Observatory for preservation of the data. The evaluation of the data and the preparation of this monograph supplement were accomplished using the computer facilities at AAVSO Headquarters. This computer hardware was purchased through grants from the National Aeronautics and Space Administration (grant awards NAGW 1493 and NAG 5-1459), the Kenilworth Fund, and the Theodore H. Dunham Fund for Astrophysical Research. We gratefully acknowledge these grants. Many AAVSO assistants helped in the preparation of the data for publication. My special thanks go to Elizabeth O. Waagen for her careful evaluation of the observations and plotting the light curves, and to E. Grant Foster for developing the computer programs for the IBM-PC compatible MS-DOS computers at AAVSO Headquarters to evaluate, plot, and prepare the data for publication. Robert S. Hill, Charles M. Jones, and Richard J. Strazdas assisted in the initial development of the computer programs to manage the large volumes of data. Barbara Silva, Donna Eldridge, Douglas Van Orsow, Young Lim, Michael Bickford, and several other student-assistants have helped in making the data computer-readable. The dedication, the many, many hours of observing, and the untiring efforts of our observers in pursuit of contributing to variable star astronomy have made this publication possible. Our very sincere thanks and gratitude go to them for their valuable astronomical contributions. Janet Akyuz Mattei Director Cambridge, Massachusetts April 1996 vi ----------------------------------------------------------------------------- PAGE vii CONTRIBUTORS TO AAVSO DATA ON SS CYGNI 1991 - 1995 AAP ABBOTT, A. PATRICK 111 | CSK CSERNIK, ANTAL 1 | AMT ADAMS, MARK T. 123 | CSM CSUKAS, MATYAS 69 | AB ALBRECHT, WILLIAM 617 | CCO CUBILLO, CARLOS F. 28 | ALN ALLISON, RUDIE J. 24 | CKB CUDNIK, BRIAN 27 | AMO AMORETTI, MAURO 2 | CDT CURRIER, DEWAYNE T. 1 | AJR ANDRESS, J. ROBERT 49 | DAH DAHLE, HAAKON 117 | ARN ARNOLD, LUC 6 | DZD DAROCZY, ZSOLT 2 | AKT ATKIN, TIMOTHY W. 3 | DAM DARRIBA MARTINEZ, ADOLFO 17 | BWY BAILEY, WAYNE 4 | DYJ DAUBY, JEAN 3 | BIV BALOGH, ISTVAN 74 | DAJ DAVIS, JACK F. 10 | BXA BARANSKI, ALEXANDER 36 | DTF DAVIS, THOMAS F. 1 | BSF BARNHART, STEPHEN 4 | DQM DECLERCQ, MIQUEL 1 | BBA BEAMAN, BARRY B. 32 | DBR DECOTTIGNIES, BERNARD 7 | BVD BEARD, DAVID J. 59 | DJO DEJONG, J. 1 | BTY BENNER, TERRY 101 | DFR DEMPSEY, FRANCIS S. 49 | BZT BERECZ, TIBOR 2 | DEK DEQUICK, KURT 56 | BBE BERENTE, BELA 6 | DNO DEREN, OSCAR A. 2 | BEB BERG, RAYMOND 42 | DTE DESLIJPERE, TOMMY 46 | BVA BERVALD, ASSAF 35 | DJN DICKINSON, JON J. 3 | BJZ BEST, JANET 3 | DPA DIEPVENS, ALFONS 513 | BIC BICHON, LAURENT 17 | DMN DIERICK, DOMINIQUE 2 | BMM BIESMANS, MARC 93 | DRG DIETHELM, ROGER 4 | BKN BIRKNER, ALAN J. 1 | DLA DILL, ALBERT G. 212 | BQR BLAKE, ROGER A. 1 | DIL DILLON, WILLIAM G. 267 | BGI BLASCO GIL, GONZALO 1 | DMY DOMBROWSKI, MARY 4 | HUO BLOOM, DONNA J. 8 | DPL DOMBROWSKI, PHILIP 205 | BAX BOATTINI, ANDREA 10 | GDB DOMENY, GABOR 24 | BOH BOHME, DIETMAR 10 | DZM DONZEL, MARC 5 | BJV BOIVIN, JEAN-FRANCOIS 2 | DUP DUPASQUIER, PAUL 5 | BOE BOREL, JAMES 16 | DJI DUSEK, JIRI 15 | BEC BORN, ECKHARD 35 | DGP DYCK, GERALD P. 678 | BRJ BORTLE, JOHN E. 473 | ELD ELIAS, DEMETRIUS P. 7 | BMU BOUMA, R. J. 391 | ELP ELIAS, PANAGIOLIS 3 | BMK BRADBURY, MARK 5 | EL ELLERBE, JAMES E. 5 | BDT BRANCHETT, DAVID W. 146 | EPE ENSKONATUS, PETER 59 | BTB BRETL, THOMAS C. 6 | EJO ERDEI, JOZSEF 1 | BSM BRINCAT, STEPHEN M. 59 | FCA FAUSEL, CHARLES A. 93 | BOS BROENS, ERIC 226 | FJH FEIJTH, HENDRIK 393 | BBT BROWNING, ROBERT R. 31 | FKJ FEKETE, JANOS 124 | BHC BRUHN, CARL 5 | FRF FIDRICH, ROBERT 89 | BOA BRUNO, ALAIN 6 | FEM FLYNN, EDWARD M. 19 | BJY BRYDGES, JEFFREY D. 12 | FSE FOGLIA, SERGIO 23 | BZB BRYLOWSKI, ZBIGNIEW 12 | FFC FOLDESI, FERENC 37 | BUK BULICKOVA, LUCIE 38 | FMR FONOVICH, MARINO 8 | BSO BURGESS, SCOTT J. 4 | FMC FRANGEUL, MICHEL 26 | BTH BURROWS, THOMAS A. 348 | FML FRIDLUND, MALCOLM 10 | BFS BUTLER JR., JAMES 10 | FAA FROSINA, ANGELO 4 | CBA CABRERA RODRIGUEZ, ANGEL 5 | FMG FUGMAN, GARY C. 45 | CMP CAMPBELL, RICHARD 73 | GMB GABLE, MARK 78 | CFN CAMPOS, FRANCISCO 23 | GBZ GABZO, OFER 522 | CEA CANDELA, BERNARD 5 | GEC GALE, EUGENE C. 2 | CDX CHALOUX, DAVID A. 11 | GCZ GANCARZ, JAMES 95 | CNT CHANTILES, DEAN 39 | GPA GARCIA, FRANCISCO 28 | CGF CHAPLE JR., GLENN F. 123 | GAA GAREY, PATRICK 5 | CJM CHAVEZ, JOSE MANUEL 2 | GJN GENSLER, JAN 35 | CTS CHRISTENSEN, THOMAS A. 1 | GKT GERGELY, KATONA 1 | CYA CICHY, ADAM 75 | GGT GLENN, GARY 26 | CIR CINTRON, ROBERT 7 | GOP GOODWIN, PAUL N. 29 | CLH CLAES, JOHAN 2 | GRL GRANSLO, BJOERN H. 305 | CLK CLARK, WAYNE E. 9 | GRI GRIESE III, JOHN W. 120 | CNL COLE ARNAL, OSCAR 13 | GCT GRUNNET, CARL 280 | COL COLLINS, PETER L. 308 | GUB GUBBELS, GUIDO 76 | CMG COMELLO, GEORG 143 | GHD GUIDRY, HOWARD 69 | CGG CONLIN, GREGORY 1 | GUN GUNTHER, JEAN 297 | CK COOK, STEPHEN P. 2 | HCS HADHAZI, CSABA 18 | CWD COWALL, DAVID E. 2 | HTY HAGER, TIMOTHY 108 | CR CRAGG, THOMAS A. 5 | HK HALBACH, EDWARD A. 138 | CCS CREIGH, CHARLES 30 | HMR HAM, RONALD 55 | CRR CRUMRINE, ROBERT E. 4 | HAN HANNON, JAMES 71 | CJK CSANYI, JANEK 3 | HSG HANSON, GENE 77 | HAV HARVAN, RICHARD P. 64 HAI HASTINGS, ALLEN 1 HSB HASUBICK, WERNER 1 HAB HAYS JR., ROBERT H. 313 HZL HAZEL, LAWRENCE 33 HEF HEIFNER, MARK A. 78 HEL HELBAK, KNUTE 7 HED HENSEL, DETLEF 37 HEV HEVESI, ZOLTAN 2 HE HIETT, F. LANCASTER 209 HWD HODGSON, WILLIAM D. 36 HEK HOEG, ERIK 6 HFO HOFFER, G. 1 HJO HOLTROP, J. 121 HZJ HOLTZ, JOHN WILLIAM 14 HOO HOOGEVEEN, GEERT 21 HRB HORNBY, PETER W. 15 HOV HORVATH, GEZA 11 HAQ HOUNVAI, ANTOL 4 HVA HOUVENAEGHEZ, ALAIN 2 HJA HUDSON, JEROME A. 5 HUR HURST, GUY M. 2 IML IDEM, MICHAEL 132 JQL JACQUIER, LUDWIG 1 JM JAMES, ROBERT A. 27 JAJ JANSSENS, JAN 7 JKK JENSEN, KARL KLINDT 38 JLT JENSEN, LASSE TEIST 268 JRJ JOHANNS, R. J. 25 JOG JOHNSON, GUS E. 91 JON JONCKHEERE, KURT 23 JSZ JOZSA, SANDOR 1 JPE JUHAROS, PETER 1 KDA KAISER, DANIEL 1 KAP KALOCZY, PETER 4 KB KAMINSKI, WALTER J. 311 KID KAPUS, ILDIKO 1 KTL KEITH, LEE 2 KAK KERESZTURI, AKOS 1 KZD KESZTHELYI, DANIEL 1 KRB KING, ROBERT P. 350 KBR KIRSHNER, BRIAN 18 KIL KISS, LASZLO 126 KON KLINTING, OLE 7 KGT KNIGHT, GEORGE 2 KSP KNIGHT, STEPHEN P. 94 KOC KOCSIS, ANTAL 26 KDF KOCYLA, DENNIS F. 1 KHL KOHL, MICHAEL 98 KRS KOLMAN, ROGER S. 130 KMA KOMOROUS, MIROSLAV 461 KOS KOSA-KISS, ATTILA 209 KOA KOSHIRO, MASAMI 1 KKO KOSS, K. 18 KTD KOUTSOTHEODORIS, THEODOR 11 KVI KOVACS, ISTVAN 11 KWO KRIEBEL, WOLFGANG 124 KIS KRISCH, GUNTHER 103 KRK KRISCIUNAS, KEVIN 6 KJI KRTICKA, JIRI 59 KBP KUBICEK, PAVEL 6 KCJ KUCERA, J. 1 KMN KUKO, MELINDA 1 KBO KUPLIN, ROBERT JOHN 2 LDT LADANYI, TAMAS 1 LAR LAMBERT, RANDY 5 LGU LAMBRECHTS, GUY 12 LTO LANGE, THORSTEN 7 LKG LARSON, KEVIN GARY 12 LVA LAUVSTAD, ANDREAS 49 vii ----------------------------------------------------------------------------- PAGE viii CONTRIBUTORS TO AAVSO DATA ON SS CYGNI (continued) 1991 - 1995 LVH LAVERGE, HANNELORE 1 | PPS PAPP, SANDOR 427 | LZT LAZUKA, THOMAS 56 | PMA PARKER, MARK 17 | LEB LEBERT, ROLAND 13 | PAK PATAK, AKOS 32 | LMA LE MAY, DAMIEN 1 | PDN PEARCE, DON C. 3 | LNZ LENZ, GEORGE F. 59 | PEI PEDERSEN, EIGIL 62 | LJL LEONARD, J. L. 2 | PEG PEGUET, CLAUDE 9 | LRD LORING, DANIEL P. 19 | PJH PERALA, JUHA 1 | LEJ LOS, EDWARD J. 4 | PMR PERALA, MARTTI R. 118 | LVT LOVETT, JAMES 182 | PAE PEREIRA, ALFREDO J. 14 | LTB LUBBERS, THOMAS F. 17 | PKI PIECHOWSKI, OTTO R. 3 | LBG LUBCKE, GILBERT C. 624 | PTZ PIETZ, JOCHEN 182 | LRE LUNSFORD, ROBERT 5 | PEY PIGGOTT, EDWARD J. 1 | MDW MACDONALD II, WALTER 30 | PSC PINAULT, STEVEN C. 11 | MDD MADDEN, PATRICK J. 2 | PBE PIOLON, BENGT 7 | MDH MADDOCKS, HUGH C. 25 | PVK POSVIK, K. 2 | MMS MAES, MICHA 3 | POX POXON, MICHAEL 172 | MLI MAISLER, LEE 183 | PYG POYNER, GARY 184 | MLT MALLAMA, ANTHONY 1 | PPR PRESITS, PETER 5 | MKE MANSKE, ROBERT P. 11 | PUJ PUJOL, FRANCISCO 48 | MJZ MANZORRO, JUAN 81 | RAA RAASCH, RICHARD W. 14 | MIC MARILLER, C. 21 | RRB RAPHAEL, ROBERT B. 17 | MRX MARX, HARALD 10 | REP REINHARD, PETER 21 | MPR MAURER, PETER 45 | RJI RIGGS, JOHN I. 11 | MGE MAVROFRIDIS, GEORGE 86 | RPR ROBBINS, PHILLIP 178 | MYR MAYER, ERNST H. 31 | RLR ROBINSON, ROBERT 3 | MJW MAYER, JAY W. 113 | RJN ROCHEFORT, JULIEN 2 | MGU MCCAGUE, THOMAS J. 40 | RMU RODRIGUEZ MARCO, MIGUEL 181 | MKJ MCKENNA, JEROME F. 126 | RGB ROSENBERG, GEORGE 3 | MIB MEDIAAS, IVAR B. 1 | RGL ROTEM, GILAD 76 | MED MEDWAY, KENNETH J. 565 | RSH ROWSE, SHANE 2 | MJL MENDEZ-ALVAREZ, JAVIER 1 | RR ROYER, RONALD E. 339 | MMY MEYER, MAIK 22 | RFN ROZSA, FERENC 1 | MDI MIDDLEMIST, IAN A. 34 | RGY RUBRIGHT, GARY 2 | MOK MIDTSKOGEN, ORNULF 453 | RIS RUZSINKA, ISTVAN 1 | MDQ MILLER, DOUGLAS C. 5 | SLX SAILLOL, ALEXANDRE 2 | MZS MIZSER, ATTILA 61 | SJQ SAJTZ, ANDRAS 20 | MCE MOCHIZUKI, ETSUIKU 27 | SSU SAKUMA, SEI-ICHI 136 | MRV MODIC, ROBERT J. 601 | SAH SAMOLYK, GERARD 1 | MOX MOELLER, GERHARD 6 | SGI SANTOS, MIGUEL 26 | MMI MOELLER, MICHAEL 478 | SPQ SAPI, CSABA 73 | MOD MOHRBACHER, DAVID 9 | SKI SARNECZKY, KRISTIAN 8 | MOL MOLNAR JR., JAMES 122 | SGE SARTY, GORDON 123 | MJ MONTAGUE, ALLEN C. 2 | SPK SCHMEER, PATRICK 295 | MF MONTAGUE, FREDERICK 2 | SLZ SCHOTT, GERD-LUTZ 130 | MOJ MORGAN, JAMES E. 23 | SSE SCHUE, MICHAEL SCOTT 5 | MOI MORILLON, ERIC 35 | SCZ SCHWEITZER, EMILE 99 | MOW MORRISON, WARREN C. 365 | SCX SCIARONI, ERNEST 2 | MDU MULINSKI, DANIEL 3 | SCE SCOVIL, CHARLES E. 95 | MUY MUYLLAERT, EDDY 11 | SHS SHARPE, STEVEN B. 116 | NZO NAGY, ZOLTAN 19 | SSA SHARPLESS, ALBERT 14 | NMS NALL, MARK S. 10 | SHQ SHEMMER, OHAD 118 | NTL NATALE, MICHAEL 3 | SHW SHERMAN, WILLIAM R. 41 | NRH NELSON, ROBERT 3 | SIH SILHOL, MAX 105 | NJO NEUMANN, JORG 3 | SNE SIMMONS, NEIL A. 88 | NBY NORDBY, JOHN M. 135 | SKP SKALAK, PETR 59 | NVK NOVAK, MICHAEL 53 | SDU SMITH, DOUGLAS 23 | ONY NYIRO, OTTO 3 | SOH SORENSEN, HANS 184 | OCN O'CONNOR, STEPHEN 19 | SJZ SPEIL, JERZY 268 | ONJ O'NEILL, JOHN G. 62 | SPO SPONGSVEEN, JUL 26 | OES OESPER, DAVID 7 | SC SPRATT, CHRISTOPHER 47 | OER OFEK, ERAN 189 | SYM SPURNEY, M. 1 | OJO OLESEN, J. OSTERGAARD 396 | SBL STAELS, BART 3 | ON ONDRA, LEOS 31 | SVD STEBLINA, VLADIMIR 42 | OV ORAVEC, EDWARD G. 21 | SKS STECKNER, THOMAS 1 | ORW ORTEL, R. WADE 3 | STI STEFFEY, PHILIP C. 125 | OJR OSORIO, JOSE RIPERO 292 | SGP STEGMANN, PAUL E. 9 | OSV OSVALD, LASLO 8 | SPU STEPAN, PETR 30 | OCR OTTEN, CHRETIEN 28 | SET STEPHAN, CHRISTOPHER 117 | PLA PADILLA FILHO, ANTONIO 20 | SWF STEWART, ALISON 1 | PCC PAPINI, RICCARDO 21 | SWT STEWART, ROBERT J. 272 | STQ STOIKIDIS, NIK 7 SQA STROBBE, JAN 14 SUX SUAREZ, MAXIMO 44 SUS SUSSMANN, DIETER 8 SVN SVENTEK, PAUL L. 38 SSW SWIERCZYNSKI, STANISLAW 67 SDX SWORIN, DAVID J. 52 SIZ SZABO, RITA 1 SBT SZABO, ROBERT 245 SXP SZAKAL, P. 3 SZX SZALMA, ZSOLT 1 SKV SZARKA, LEVENTE 53 SNO SZENTASKO, LASZLO 294 SZK SZITKAY, GABOR 4 SOO SZOLLOSI, ATTILA 10 SUZ SZUTOR, PETER 6 TDB TAYLOR, DANIEL 239 TSZ TEICHNER, SZILARD 2 TBA TEKATCH, BARBARA 49 TPH TENGG, PHILLIP 2 TOK TENKEI, OLGA 1 TPS TEPLICZKY, ISTVAN 32 TAX THOMAS, AXEL 3 THR THOMPSON, RAYMOND 5 THU THOUET, BERNARD 13 TIA TIMAR, ANDRAS 17 TRL TOGNI, ROBERT L. 23 TMB TOMBELLI, MAURA 18 TRT TORDAI, TAMAS 37 TTJ TOTH, JANOS 1 TTK TOTH, KRISZTIAN 4 TTH TOTH, TAMAS 15 TSC TRACY, SCOTT 45 TDM TROIANI, DANIEL M. 50 TSJ TSUJI, SEIJI 16 VMN VAMOSI, MARTON 2 VCP VAN CAUTEREN, PAUL 125 VDE VAN DIJK, E. 20 VNL VAN LOO, F. R. 188 VDL VANDERLOVY, JOHAN 60 VDJ VANDIJK, J. F. H. 46 VHD VANHESSCHE, DIRK 49 VMT VANMUNSTER, TONNY 318 VSJ VANSTEELANDT, JAN 2 VZS VARGA, ZSAZSA 2 VED VEDRENNE, PAUL 490 VPE VELESCHUK, PETER 5 VET VERDENET, MICHEL 403 VIA VIALLE, JACQUES 57 VNZ VICIAN, ZOLTAN 19 VJF VIENS, JEAN-FRANCOIS 165 VGP VIGNIER, PHILLIPE 7 VFK VOHLA, FRANK 92 VOL VOLLMANN, WOLFGANG 12 VVI VOROSHAZI, VILLO 4 WKP WALKER, PAUL 62 WND WALLIAN, DENIS 2 WRS WATT, RICHARD S. 6 WPU WEEKS, PAUL 6 WEI WEIER, DAVID D. 81 WJU WEIER, JOSHUA D. 4 WC WEND, RICHARD E. 177 WET WESELAK, TOMESZ 8 WEJ WEST, E. JAMES W. 86 WTJ WEST, JOHN 1 WTK WIESZT, KRISTIEN 6 WI WILLIAMS, DAVID 63 WJY WILMS, JOHNNY 17 WLP WILS, PATRICK 10 WDN WILSON, DANNY RAY 144 viii ---------------------------------------------------------------------------- PAGE ix CONTRIBUTORS TO AAVSO DATA ON SS CYGNI (continued) 1991 - 1995 WRO WRIGHT, ROBERT 3 | ZFE ZAGYI, FERENC 2 | YRK YORK, DAVID O. 635 | ZAG ZAJACZ, GYORGY 37 | ZLT ZALEZSAK, TAMAS 11 ZRE ZISSELL, RONALD E. 37 CONTRIBUTING ASTRONOMICAL ORGANIZATIONS Agrupacia Astronomica Albireo of Seville (Spain) Asociacion Argentina Amigos de la Astronomia Association Francaise des Observateurs d'Etoiles Variables (France) Astronomical Society of Southern Africa, Variable Star Section Astronomischer Jugendclub (Austria) Astronomisk Selskab (Scandinavia) British Astronomical Association, Variable Star Section (England) British Astronomical Association of New South Wales (Australia) Bundesdeutsche Arbeitsgemeinschaft fur Veranderliche Sterne e.V.(BAV) (Germany) Grupo Astronomico Silos (Zaragoza, Spain) Grupo Canario de Estrellas Variables (Canary Islands, Spain) Israeli Astronomical Association, Variable Star Section Madrid Astronomical Association M1 (Spain) Liga Ibero-Americana de Astronomia (South America) Magyar Csillagaszati Egyesulet, Valtozocsillag Szakcsoport (Hungary) Nederlandse Vereniging Voor Weer-en Sterrenkunde, Werkgroep Veranderlijke Sterren (Netherlands) Norsk Astronomisk Selskap, Variable Stjernegruppen (Norway) Planetario e Observatorio Astronomico do Colegio Estadual do Parana (Brazil) Red de Observatores de Estrellas Variables - MIRA (Spain) Royal Astronomical Society of Canada Royal Astronomical Society of New Zealand, Variable Star Section Sociedad Astronomica 'Syrma' (Valladolid, Spain) Svensk Amator Astronomisk Forening, variabelsektionen (Sweden) Uniao Brasileira deAstronomia, Variable Star Commission (Brazil) Unione Astrofili Italiani (UAI) Variable Star Observers League in Japan Vereniging Voor Sterrenkunde, Werkgroep Veranderlijke Sterren (Belgium) ix ----------------------------------------------------------------------------- PAGE x INFORMATION ON SS CYGNI Right Ascension Declination Position: (1900) 21h 38m 47s +43 degrees 07.7' (1950) 21 40 45 +43 21.4 (2000) 21 42 42 +43 35.0 Type: Cataclysmic variable - dwarf nova of U Geminorum type Average Outburst Frequency: 50 days Orbital Period: 0.275130 day (06:36:11) Spectrum (secondary): K5V Mass Ratio (primary/secondary): 1.70 +/- 0.04 Mass (primary): 1.33 solar masses Mass(secondary): 0.80 solar mass Orbital Inclination: 38 degrees Other Information: X-ray source (hard and soft x-ray) KEY TO SYMBOLS Symbols used in this monograph are: . = 1 visual observation v = variable is fainter than the magnitude indicated by the vertex of the "v" on the light curve (variable not seen) Please note that there may appear to be horizontal lines in some parts of the light curves. These horizontal "lines" are in fact very dense concentrations of individual observations. There are also some clusters of observations that appear as vertical lines on the light curves. These vertical "lines" are observations made using CCD and have magnitudes reported to two or three decimal places. x ----------------------------------------------------------------------------- PAGE xi SS CYGNI LIGHT CURVES 1991 - 1995 -------END OF FILE------------------------------------------------------------