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: 2138+43 SS CYG 1854+30 DM LYR No. 639 0206+57A TZ PER 1925+42 V1504 CYG June 27, 2000 1640+25 AH HER ---------------------------------------------------------------------------- 2138+43 SS CYGNI The critical need for your nightly observations of SS Cyg continues! Astronomers at Lawrence Livermore National Laboratory and the University of Leicester are waiting for us to inform them of SS Cyg's going into outburst. At that time they will trigger observations with the Chandra, RXTE, and EUVE satellites. SS Cyg may go into outburst at any moment now, especially given its recent behavior, so it is essential that we keep a very close eye on it. We realize that rain and clouds are affecting many observing sites around the world at present. Therefore, we strongly urge any observers who can observe SS Cyg to do so and to report their observations to AAVSO Headquarters. You are a crucial part of this complex observing run and we very much appreciate your valuable contribution. ---------------------------------------------------------------------------- 0206+57A TZ PERSEI The dwarf nova type (Z CAM subclass) cataclysmic variable TZ PER appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUN 19.019 <13.6 MUY JUN 27.067 13.0 PYG JUN 19.056 <13.5 PYG ---------------------------------------------------------------------------- 1640+25 AH HERCULIS The dwarf nova type (Z CAM subclass) cataclysmic variable AH HER appears to be brightening, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUN 23.918 13.5 OJR JUN 25.942 13.1 MUY JUN 23.930 13.8 RMQ JUN 26.1813 13.0 SXN JUN 24.1181 12.8 DPL JUN 26.90 12.4 VET JUN 25.1924 13.2 HSG JUN 26.986 12.3 PYG JUN 25.363 12.8 LMK JUN 27.381 12.5 LMK JUN 25.923 12.7 RMQ ---------------------------------------------------------------------------- 1854+30 DM LYRAE The dwarf nova type cataclysmic variable DM LYR may be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUN 25.1944 <16.0 HSG JUN 26.2243 <13.0 SXN JUN 25.937 <15.2 RMQ JUN 27.017 15.5: PYG ---------------------------------------------------------------------------- 1925+42 V1504 CYGNI The dwarf nova type (SU UMA subclass) cataclysmic variable V1504 CYG is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUN 24.986 <15.7 RMQ JUN 26.9917 14.39 CCD DRG JUN 26.3181 <14.5 SXN JUN 27.033 14.6 PYG ---------------------------------------------------------------------------- We thank the following contributors for the data that they have provided for this News Flash: DPL - P. DOMBROWSKI, USA OJR - J. OSORIO, SPAIN DRG - R. DIETHELM, SWITZERLAND PYG - G. POYNER, ENGLAND HSG - G. HANSON II, USA RMQ - M. RESZELSKI, POLAND LMK - M. LINNOLT, USA SXN - M. SIMONSEN, USA MUY - E. MUYLLAERT, BELGIUM VET - M. VERDENET, FRANCE 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 Rebecca Pellock, 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! ____________________________________________________________________________