THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS 25 Birch Street, Cambridge, MA 02138 USA Tel. 617-354-0484 Fax 617-354-0665 http://www.aavso.org * * * AAVSO NEWS FLASH * * * Subject: 1216+05 SN 1999GN 1129-11 TT CRT No. 547 0207-63 WX HYI 1344+08 CR BOO December 20, 1999 0434+50 FY PER 1918+04 V1494 AQL(update) 0434-04 BF ERI 1953+77 AB DRA 0611+15 CZ ORI 2023+43 V503 CYG 0939-20 SN 1999GH(update) 2043+41 V516 CYG 0945+12 X LEO 1012+41 SN 1999GI(update) ---------------------------------------------------------------------------- 1216+05 SUPERNOVA 1999gn IN NGC 4303 = M61 We have been informed by the Central Bureau for Astronomical Telegrams (IAU Circular 7335 - http://cfa-www.harvard.edu/iau/cbat.html) that Alessandro Dimai, Cortina, Italy, discovered an apparent supernova in NGC 4303 (= M61) on Dec. 17.22 UT at unfiltered CCD magnitude 16.0, using a 0.50-m telescope. W. Li, University of California at Berkeley, reported that the supernova was unfiltered CCD magnitude 15.5 on an image taken with the Katzman Automatic Imaging Telescope (KAIT) on Dec. 18.5 UT. A precise position of SN 1999gn, which is 31.7" east and 39.8" south of the nucleus of the galaxy, was measured by Li as: R.A. = 12h 21m 57.02s Decl.= +04 degrees 27' 45.6" (Equinox 2000.0) For more information and a chart please see AAVSO Alert Notice 268 which is avaialable through the AAVSO web site at the follwing address: http://www.aavso.org Congratulations to Alessandro Dimai on his discovery! ---------------------------------------------------------------------------- 0207-63 WX HYDRI The dwarf nova type (SU UMA subclass) cataclysmic variable WX HYI appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 14.79 14.0 MLF DEC 19.5083 <14.0 SRX DEC 17.4632 <13.7 SRX DEC 20.5167 12.5 SRX ---------------------------------------------------------------------------- 0434+50 FY PERSEI The dwarf nova type (Z CAM subclass) cataclysmic variable FY PER appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 08.2778 <13.5 SXN DEC 19.2188 12.0 SXN ---------------------------------------------------------------------------- 0611+15 CZ ORIONIS The dwarf nova type cataclysmic variable CZ ORI is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 14.010 <15.0 PYG DEC 17.7104 12.6 SRX DEC 14.4764 <13.4 SRX DEC 18.2549 12.5 SXN DEC 14.883 <13.9 MUY DEC 19.5181 12.4 SRX DEC 15.879 <13.9 MUY DEC 19.990 12.6 PYG DEC 17.4653 <13.0 SRX ---------------------------------------------------------------------------- 0939-20 SN 1999GH We have received the following observations of the recent supernova, SN 1999GH;since the release of News Flash No. 544: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 18.389 15.7 CCDV OCN DEC 19.363 15.8 CCDV OCN ---------------------------------------------------------------------------- 0945+12 X LEONIS The dwarf nova type cataclysmic variable X LEO appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 14.6736 <14.0 SRX DEC 18.3819 12.7 SXN DEC 17.7097 12.5 SRX ---------------------------------------------------------------------------- 1012+41 SN 1999GI We have received the following observations of the recent supernova, SN 1999GI;since the release of News Flash No. 544: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 17.95 14.1 CCD BEN DEC 19.379 14.5 MRV ---------------------------------------------------------------------------- 1129-11 TT CRATERIS The dwarf nova type cataclysmic variable TT CRT appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 05.6931 <14.2 SRX DEC 14.6806 13.6 SRX DEC 13.6403 13.8 SRX DEC 17.7278 13.4 SRX ---------------------------------------------------------------------------- 1344+08 CR BOOTIS The dwarf nova type cataclysmic variable CR BOO appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials NOV 21.5333 <14.1 HSG DEC 18.4417 13.5 SXN ---------------------------------------------------------------------------- 1918+04 V1494 AQUILAE Following are observations of the new nova in Aquila that have been submitted to the AAVSO since the release of News Flash No. 545: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 08.003 5.6 MRV DEC 18.9700 7.0 CLQ DEC 09.9771 5.8 BVE DEC 18.9722 6.8 MGQ DEC 11.962 6.4 MRV DEC 18.9757 6.7 MHI DEC 15.678 6.4 GRL DEC 19.0000 6.8 BEB DEC 16.84 6.5 PDQ DEC 19.097 7.1 LMK DEC 17.667 6.6 ZAG DEC 19.458 7.0: GUS DEC 17.6861 6.7 REP DEC 19.6604 7.0 SBX DEC 17.6979 6.6 VOL DEC 19.698 7.2 GRL DEC 17.722 6.5 PYG DEC 19.7083 7.0 JCN DEC 17.7958 6.5 AJO DEC 19.7222 7.0 LME DEC 17.9070 6.7 TYS DEC 19.723 7.6 RCH DEC 17.9257 6.5 DPL DEC 19.74 6.8 CMH DEC 17.9542 6.6 GLG DEC 19.75 7.1 VET DEC 17.9590 6.7 BRJ DEC 19.7528 7.9 VFK DEC 18.451 6.8 GUS DEC 19.7611 7.4 CMG DEC 18.658 6.7 GRL DEC 19.937 7.5 OCN DEC 18.750 7.0 OJR DEC 19.9479 7.7 DPL DEC 18.7521 6.8 ZAM DEC 19.9722 7.3 AWI DEC 18.9389 6.7 DPL DEC 19.9812 6.9: BVE DEC 18.940 6.8 OCN DEC 20.097 7.3 LMK DEC 18.9577 6.9 GLG ---------------------------------------------------------------------------- 1953+77 AB DRACONIS The dwarf nova type (Z CAM subclass) cataclysmic variable AB DRA is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 14.739 <14.0 MUY DEC 17.8819 13.0 JCN DEC 15.751 14.9 PYG DEC 17.9785 12.5 BRJ DEC 17.738 13.0 PYG DEC 19.7667 13.5 JCN ---------------------------------------------------------------------------- 2023+43 V503 CYGNI The dwarf nova type (SU UMA subclass) cataclysmic variable V503 CYG appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 17.825 <14.6 PYG DEC 19.804 13.8 PYG ---------------------------------------------------------------------------- 2043+41 V516 CYGNI The dwarf nova type (SS CYG subclass) cataclysmic variable V516 CYG is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 10.0560 15.82 ZRE DEC 17.823 <15.0 PYG DEC 10.736 <14.2 MUY DEC 17.9764 14.3 BRJ DEC 13.872 <15.0 PYG DEC 19.801 14.0 PYG DEC 14.728 <14.2 MUY ---------------------------------------------------------------------------- We thank the following contributors for the data that they have provided for this News Flash: AJO - J. AFONSO R. MARTINS, PORTUGAL MLF - L. MONARD, SOUTH AFRICA AWI - W. ANTHONY, USA MRV - R. MODIC, USA BEB - R. BERG, USA MUY - E. MUYLLAERT, BELGIUM BEN - E. BERKO, HUNGARY OCN - S. O'CONNOR, CANADA BRJ - J. BORTLE, USA OJR - J. OSORIO, SPAIN BVE - E. VAN BALLEGOY, NETHERLANDS PDQ - D. PROUST, FRANCE CLQ - L. CASON, USA PYG - G. POYNER, ENGLAND CMG - G. COMELLO, NETHERLANDS RCH - C. RAMILLON, FRANCE CMH - M. CHAPELET, FRANCE REP - P. REINHARD, AUSTRIA DPL - P. DOMBROWSKI, USA SBX - A. SONKA, ROMANIA GLG - G. GLIBA, USA SRX - R. STUBBINGS, AUSTRALIA GRL - B. GRANSLO, NORWAY SXN - M. SIMONSEN, USA GUS - S. GURYANOV, RUSSIA TYS - R. TYSON, USA HSG - G. HANSON II, USA VET - M. VERDENET, FRANCE JCN - C. JONES, ENGLAND VFK - F. VOHLA, GERMANY LME - M. LYONS, ENGLAND VOL - W. VOLLMANN, AUSTRIA LMK - M. LINNOLT, USA ZAG - G. ZAJACZ, HUNGARY MGQ - G. MENALI, USA ZAM - M. ZANOTTA, ITALY MHI - H. MENALI, USA ZRE - R. ZISSELL, USA Please monitor these and other variable stars closely and phone-in, fax, or e-mail your observations to the AAVSO. Good observing! Janet A. Mattei, Director Gamze Menali, Technical Assistant ____________________________________________________________________________ Symbols may include: < = fainter than magnitude given (variable not seen) : = uncertain CCDV = Charge-coupled device with (V) filter If you would like to contribute to AAVSO NEWS FLASH, please send observations of unusual variable star activity to: observations@aavso.org Those who wish to subscribe (free of charge) or unsubscribe to NEWS FLASH may do so by visiting the following web page: http://www.aavso.org If you would like data from the AAVSO International Database for research purposes, please send your request to: Janet Mattei, AAVSO Director, at aavso@aavso.org An archive of past issues of the News Flash is available at the following web page: http://www.aavso.org/newsflash/ We look forward to including your observations in future editions of AAVSO NEWS FLASH! ____________________________________________________________________________