PAGE 1 U G E M I N O R U M L I G H T C U R V E S 1 9 8 5 - 1 9 9 0 AAVSO MONOGRAPH 2 SUPPLEMENT 1 This monograph is dedicated to Keith H. and Sylvia S. Danskin in recognition of their service and many contributions to the Association. Prepared by Janet A. Mattei Elizabeth O. Waagen E. Grant Foster Funds for preparation and publication provided by Keith H. and Sylvia S. Danskin Clinton B. Ford Additional funds provided by AAVSO Members International Astronomical Union (IAU) PAGE ii ISBN 1-878174-06-1 COPYRIGHT 1991 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 U Geminorum vii Information on U Geminorum ix Key to Symbols ix Light Curves of U Geminorum, 1985 - 1990 1 PAGE iv is blank PAGE v U GEMINORUM LIGHT CURVES, 1985 - 1990 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. U Geminorum Light Curves, 1985 - 1990 AAVSO Monograph 2, Supplement 1, contains light curves of U Geminorum from 1985 through 1990. Pages 1 through 12 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 0) 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 U Geminorum and a Key to Symbols are given on page ix. Observations from JD 2446000 to 2446064 were also published in Monograph 2. They are repeated in this supplement to make the first light curve more complete. The observations in this supplement are the contributions of AAVSO members or observers in the United States and abroad. 287 observers have contributed 10,361 observations to these light curves. The names and observer codes of these observers are given on pages vii through viii. In preparing the data for publication, each observation was evaluated for accuracy by my 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 1985 through 1990 included in this monograph have been preserved on magnetic tape, cartridge, and printout. Electronic, diskette, magnetic tape, or printout copies of observations for further analysis may be obtained by writing to the AAVSO Director. Acknowledgements We dedicate this monograph to Keith H. and Sylvia S. Danskin. Keith and Sylvia have contributed generously towards the preparation of this supplement and we extend our very sincere thanks to them. Our special thanks go to 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 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. We acknowledge with thanks the computer support of the Smithsonian Astrophysical Observatory for the processing of part of the data and data preservation. 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, 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 October 1991 vi PAGE vii CONTRIBUTORS TO AAVSO DATA ON U GEMINORUM 1985 - 1990 AAP A. Abbott 30 FRF R. Fidrich 32 LJS J. Lavigne 11 AD R. Adams 5 FHO H. Fish 1 LZT T. Lazuka 21 AB W. Albrecht 534 FDV D. Fisher 25 LKD D. Leake 10 AOD O. Andersen 4 FDA A. Fodor 3 LNB G. Lindbloom 3 ARI R. Ariail 54 FDC F. Fodor 8 LJK J. Lingaas 30 BOZ B. Bago 13 FFC F. Foldesi 18 LWT T. Lohvinenko 2 BVE E. Ballegoy 2 GSR R. Geschwind 9 LVT J. Lovett 17 BEW W. Barnes 6 GHO L. Ghio 1 LBG G. Lubcke 38 BSR S. Baroni 2 GDI D. Gill 3 LRE R. Lunsford 1 BJS J. Bedient 1 GFB W. Goff 8 LBB B. Lux 4 BTY T. Benner 70 GOT T. Gomez 6 LYR R. Lynch 1 BBE B. Berente 1 GNZ G. Gonzalez 2 MKE R. Manske 12 BNS S. Bergeron 1 GOP P. Goodwin 52 MCO M. Marcario 1 BML M. Bernstrom 111 GKA K. Graham 2 MAS A. Marosi 1 BIC L. Bichon 23 GDP P. Granaud 3 MSM M. Masson 1 BAX A. Boattini 15 GRL B. Granslo 234 MTH H. Matsuyama 4 BFK F. Boinck 2 GRI J. Griese III 140 MGE G. Mavrofridis 5 BYR J. Bondono 33 GRS J. Grissom 2 MYR E. Mayer 240 BRJ J. Bortle 171 GSC C. Gros 10 MGU T. McCague 25 BMU R. Bouma 27 GML M. Grunanger 4 MCM M. McCants 1 BDS R. Boyd 4 GRZ H. Grzelczyk 60 MGG G. McGinnis 9 BDL D. Breslin 1 GMM M. Gumler 7 MGT R. McGwier 1 BSM S. Brincat 18 GUN J. Gunther 127 MKJ J. McKenna 82 BBT R. Browning 82 HTY T. Hager 51 MBC B. McMillan 41 BOA A. Bruno 3 HK E. Halbach 24 MIB I. Mediaas 4 BYD R. Bryden 12 HSG G. Hanson 11 MED K. Medway 391 CBA A. Cabrera-Rodriguez 1 HPR C. Harper 5 MDG D. Megginson 47 CMP R. Campbell 101 HAV R. Harvan 88 MEZ C. Mezosi 1 CPA A. Camponovo 10 HAB R. Hays 70 MOK O. Midtskogen 232 CEA B. Candela 23 HZL L. Hazel 2 MIU M. Mikutis 2 CPK P. Carpreau 2 HEF M. Heifner 85 MTL R. Milton 4 CGW W. Carragan 1 HEL K. Helbak 1 MJI J. Miner 1 CJR J. Caruso 3 HE F. Hiett 84 MIS J. Minois 35 CGF G. Chaple 226 HIM M. Hill 8 MZS A. Mizser 85 TCE E. Cifuentes-Torres 19 HIR Y. Hirasawa 145 MCE E. Mochizuki 14 CLK W. Clark 18 HWD W. Hodgson 2 MMI M. Moeller 162 COL P. Collins 75 HRB P. Hornby 2 MGY I. Mogyorosi 1 CMG G. Comello 72 HSR S. Hoste 4 MOL J. Molnar 3 CGG G. Conlin 21 HR C. Hurless 17 MAR R. Monella 6 COO L. Cook 172 IML M. Idem 664 MDE D. Monger 25 CK S. Cook 9 IFJ F. Ives 2 MOR R. Monske 7 COM T. Cooper 4 IAZ A. Izumo 1 MJ A. Montague 21 COW H. Coward 2 JCT T. Jacobs 15 MOJ J. Morgan 44 CLX L. Cox 9 JM R. James 1 MOI E. Morillon 9 CR T. Cragg 68 JJT J. Jeffrey 29 MNS S. Munier 1 CRW W. Cramer 1 JOG G. Johnson 45 MJC M. Murphy 16 CRR R. Crumrine 11 JR R. Johnsson 18 MUY E. Muyllaert 11 CZT T. Csiszar 1 KDA D. Kaiser 3 NBR B. Nelson 1 CSM M. Csukas 3 KB W. Kaminski 18 NRH R. Nelson 15 DAK K. Danskin 2 KPS P. Kane 2 NGU J. Ngyuen 3 DLS Les Darling 1 KRB R. King 178 NVK M. Novak 39 DLI Lisa Darling 1 KGT G. Knight 23 NOG G. Nowak 5 DTA T. Darvann 16 KSP S. Knight 75 OJO J. Olesen 2 DYJ J. Dauby 2 KDF D. Kocyla 3 OJR J. Osorio 207 DBF F. Deboosere 2 KHL M. Kohl 8 OB M. Overbeek 6 DEA R. DeMartino 27 KLR T. Kolar 4 PLA A. Padilla-Filho 38 DNO O. Deren 1 KRS R. Kolman 14 PJZ J. Palanki 1 DPA A. Diepvens 12 KMA M. Komorous 50 PPS S. Papp 110 DIL W. Dillon 9 KRF R. Konior 3 PLI L. Parmeggiani 1 DRX R. Dixon 1 KRT S. Korth 4 PRN R. Patrick 9 DPL P. Dombrowski 119 KOS A. Kosa-Kiss 10 PEI E. Pedersen 14 GDB G. Domeny 3 KOA M. Koshiro 11 PEG C. Peguet 3 DRY R. Ducoty 71 KRR R. Kringel 2 PMR M. Perala 140 DGP G. Dyck 837 KIS G. Krisch 5 PZA A. Perez-Revilla 75 ECJ J. Eckendorf 3 KRK K. Krisciunas 4 PED D. Pettengill 136 EWH W. Edwards 5 KRP P. Kroner 1 PMI M. Potter 2 EIE C. Eiers 5 KRU J. Kruta 8 PWR D. Powaski 1 EJT J. Emmert 25 KPG G. Kuipers 22 POX M. Poxon 1 EJL J. Everaert 3 LGT G. Lacassin 47 RJT J. Reed 1 FSV S. Falvo 11 LTW T. Langhans 52 RJI J. Riggs 88 FCA C. Fausel 25 LKG K. Larson 9 RGP P. Roggemans 4 FJH H. Feijth 170 LDR D. Laurent 1 RSW W. Rosenthal 1 vii PAGE vii CONTRIBUTORS TO AAVSO DATA ON U GEMINORUM (cont'd) 1985 - 1990 RLU L. Rossi 8 SMI A. Smith 15 TDM D. Troiani 31 RO J. Rousom 1 SMQ M. Smith 29 VCP P. van Cauteren 1 RR R. Royer 70 SRQ R.K. Smith 1 VNL F. van Loo 7 RJV J. Ruiz 3 SRV R.V. Smith 1 VED P. Vedrenne 32 SGT I. Sagodi 1 SPO J. Spongsveen 3 VRG R. Venne 1 SJQ A. Sajtz 7 SSP P. Stamus 9 VET M. Verdenet 296 SSU S. Sakuma 143 STR R. Stanton 7 VNZ Z. Vician 3 SAH G. Samolyk 23 SKS T. Steckner 4 VGP P. Vignier 63 SVT T. Saville 2 STI P. Steffey 46 VGJ G. Vinci 16 SCK B. Schaefer 3 SGP P. Stegmann 3 WEI D. Weier 35 SCQ T. Schell 23 SET C. Stephan 12 WC R. Wend 9 SPK P. Schmeer 40 STF G. Stephanopoulos 50 WTJ J. West 5 SMF F. Schmidt 1 SWT R. Stewart 13 WI D. Williams 4 SCY A. Schroyens 9 SAX A. Studer 2 WLP P. Wils 7 SDH D. Schroyens 3 SGM M. Sugarman 2 WSN T. Wilson 91 SCZ E. Schweitzer 29 SVN P. Sventek 127 WMI M. Wright 8 SCE C. Scovil 147 SNO L. Szentasko 1 YRK D. York 2 SEZ J. Segonzat 2 TZR R. Tanzer 1 YON R. Young 6 SHS S. Sharpe 17 TPI P. Tassie 1 YUR J. Yurchesyn 1 SSA A. Sharpless 2 TDB D. Taylor 76 ZLT T. Zalezsak 10 SIH M. Silhol 4 TPS I. Tepliczky 2 ZAM M. Zanotta 8 SNE N. Simmons 3 THR R. Thompson 1 ZPA P. Zeller 11 SBS S. Singer-Brewster 5 TJO J. Tobin 1 ZRE R. Zissell 51 SOF O. Skjaeraasen 2 T9 K. Tomita 6 CONTRIBUTING ASTRONOMICAL ORGANIZATIONS 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) Berliner Arbeitsgemeinschaft fur Veranderliche Sterne (West Germany) British Astronomical Association, Variable Star Section (England) British Astronomical Association of New South Wales (Australia) Liga Ibero-Americana de Astronomia (South America) 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) Pleione Valtozocsillageszlelo Halozat (Hungary) Red de Observatores de Estrellas Variables - MIRA (Spain) Royal Astronomical Society of Canada Royal Astronomical Society of New Zealand, Variable Star Section Scandinavian Astronomisk Selskap Uniao Brasileira de Astronomia, Variable Star Commission (Brazil) Variable Star Observers League in Japan Vereniging Voor Sterrenkunde, Werkgroep Veranderlijke Sterren (Belgium) viii PAGE ix INFORMATION ON U GEMINORUM Right Ascension Declination Position: (1900) 07h 49m 10s +22o 15.9' (1950) 07 52 08 +22 08.1 (2000) 07 55 06 +22 00.2 Type: Cataclysmic variable - dwarf nova of U Geminorum type Average Outburst Frequency: 102 days Orbital Period: 0.176906 day (04:14:45) Spectrum (secondary): M4.5V Mass Ratio (primary/secondary): 2.09 +/- 0.15 Mass (primary): 1.18Mo +/- 0.15 Mass(secondary): 0.56Mo +/- 0.06 Orbital Inclination: 67 degrees +/- 8 Other Information: - Occurrence of transient oscillations of low coherency - Occurrence of eclipses (1 eclipse per orbital revolution) - Double-line spectroscopic binary - X-ray source (hard and soft x-ray) : KEY TO SYMBOLS Symbols used in this monograph are: . = 1 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 areas of the light curves. These "lines" are in fact very dense concentrations of individual observations. ix PAGE x U GEMINORUM LIGHT CURVES 1985 - 1990