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: 0103+95 HT CAS 1937+21 FY VUL No. 473 1640+25 AH HER 1953+77 AB DRA July 28, 1999 ---------------------------------------------------------------------------- 0103+95 HT CASSIOPEIAE The dwarf nova type (SU UMA subclass) cataclysmic variable HT CAS appears to be fading. We received 85 observations last night (1-BRJ, 1-DPL, 2-MUY, 25-PYG, 56-ZRE) which indicate that HT Cas has faded to magnitde 13.6 (as of July 28.3 UT.) This outburst does not appear to be a superoutburst as we had suspected, but rather a norrow outburst similar to the 5 outbursts (in '85, '87, '95, '97, '98) of HT Cas which have occured since the superoutburst of 1985. ---------------------------------------------------------------------------- 1640+25 AH HERCULIS The dwarf nova type (Z CAM subclass) cataclysmic variable AH HER is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUL 21.0850 13.87 CCDV ZRE JUL 25.92 11.8 VER JUL 21.1104 13.6 BRJ JUL 26.0920 12.37 CCDV ZRE JUL 21.957 13.7 RMQ JUL 26.905 11.9 MUY JUL 22.987 13.6 PYG JUL 28.0940 11.72 CCDV ZRE JUL 23.1479 13.5 SXN JUL 28.0972 10.9 BRJ JUL 23.951 12.7 PYG JUL 28.1403 11.6 DPL JUL 24.2285 12.7 BTH ---------------------------------------------------------------------------- 1937+21 FY VULPECULAE The dwarf nova type (Z CAM subclass) cataclysmic variable FY VUL appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUL 23.038 14.6 PYG JUL 26.930 13.8 MUY JUL 24.011 14.6 PYG ---------------------------------------------------------------------------- 1953+77 AB DRACONIS The dwarf nova type (Z CAM subclass) cataclysmic variable AB DRA appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUL 23.974 14.7 PYG JUL 26.913 14.0 MUY JUL 25.2757 <13.4 SXN JUL 28.1090 12.5 BRJ ---------------------------------------------------------------------------- We thank the following contributors for the data that they have provided for this News Flash: BRJ - J. BORTLE, USA RMQ - M. RESZELSKI, POLAND BTH - T. BURROWS, USA SXN - M. SIMONSEN, USA DPL - P. DOMBROWSKI, USA VER - B. VAN DER ENDE, CANADA MUY - E. MUYLLAERT, BELGIUM ZRE - R. ZISSELL, USA PYG - G. POYNER, ENGLAND 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! ____________________________________________________________________________