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 REMINDER No. 669 0207-63 WX HYI 1817+38 V391 LYR September 7, 2000 0217+70 AM CAS 1925+42 V1504 CYG ---------------------------------------------------------------------------- 2138+43 SS CYGNI REMINDER The critical need for your nightly observations of SS Cyg continues! Due to problems with the High Energy grating of Chandra's spectrometer, the ToO observations of SS Cyg could not be scheduled during its last outburst. The problems have been resolved and astronomers at Lawrence Livermore National Laboratory and the University of Leicester are now waiting for us to inform them of the beginning SS Cyg's next outburst. At that time they will trigger the observations with the Chandra, RXTE, and EUVE satellites. It is essential that we keep a very close eye on this variable. SS Cyg is a bit overdue and may go into outburst any day now. (It has been 60 days since the beginning of the last outburst, while the average interval is only 50 days.) We strongly urge you to observe SS Cyg and report your observations to AAVSO Headquarters. Thank you for your invaluable help with this campaign! ---------------------------------------------------------------------------- 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 SEP 03.777 <14.0 SRX SEP 05.514 12.4 SRX SEP 05.514 12.4 SRX ---------------------------------------------------------------------------- 0217+70 AM CASSIOPEIAE The dwarf nova type (Z CAM subclass) cataclysmic variable AM CAS is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials SEP 02.916 15.2: RMQ SEP 06.822 14.3 RMQ SEP 04.892 <14.1 MUY SEP 06.882 14.4 MUY SEP 05.966 <14.2 OJR SEP 06.9826 14.0: DPV SEP 06.1931 <14.5 SXN ---------------------------------------------------------------------------- 1817+38 V391 LYRAE The dwarf nova type (Z CAM subclass) cataclysmic variable V391 LYR appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials SEP 02.892 <15.2 RMQ SEP 06.79 14.1 KTO ---------------------------------------------------------------------------- 1925+42 V1504 CYGNI The dwarf nova type (SU UMA subclass) cataclysmic variable V1504 CYG appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials SEP 02.905 <15.0 RMQ SEP 06.835 <14.5 MUY SEP 06.1354 <14.5 SXN SEP 06.9340 <14.7 DPV SEP 06.80 14.8 KTO ---------------------------------------------------------------------------- We thank the following contributors for the data that they have provided for this News Flash: DPV - P. DUBOVSKY, SLOVAKIA RMQ - M. RESZELSKI, POLAND KTO - T. KINNUNEN, FINLAND SRX - R. STUBBINGS, AUSTRALIA MUY - E. MUYLLAERT, BELGIUM SXN - M. SIMONSEN, USA OJR - J. OSORIO, SPAIN 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! ____________________________________________________________________________