THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS 25 Birch Street, Cambridge, MA 02138 USA Tel. 617-354-0484 Fax 617-354-0665 INTERNET: aavso@aavso.org * * * AAVSO NEWS FLASH * * * Subject: AT Cnc, V503 Cyg, CZ Ori, No. 300 RY Ser, ER UMa May 19, 1998 ---------------------------------------------------------------------------- AT CANCRI The dwarf nova type (Z Cam subclass) cataclysmic variable AT Cnc is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials MAY 17.9000 <14.0 BMM MAY 18.3771 13.3 SRX MAY 18.0819 14.1 BRJ MAY 19.0833 13.0 BRJ ---------------------------------------------------------------------------- V503 CYGNI The dwarf nova type (SU UMa subclass) cataclysmic variable V503 Cyg is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials MAY 10.042 <15.0 PYG MAY 19.056 13.3 PYG MAY 14.2560 18.27 CCDV ZRE MAY 19.2510 13.94 CCDV ZRE ---------------------------------------------------------------------------- CZ ORIONIS The dwarf nova type (U Gem subclass) cataclysmic variable CZ Ori may be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials APR 21.1722 <14.4 HSG MAY 18.3667 12.6 SRX MAY 04.3840 <12.6 SRX ---------------------------------------------------------------------------- RY SERPENTIS The dwarf nova type (U Gem subclass) cataclysmic variable RY Ser appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials MAY 02.6063 <14.5 SRX MAY 18.5222 13.8 SRX MAY 18.5139 13.8 SRX ---------------------------------------------------------------------------- ER URSAE MAJORIS The dwarf nova type (SU UMa subclass) cataclysmic variable ER UMa is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials MAY 16.1660 15.1: HSG MAY 18.0896 13.9 BRJ MAY 16.9514 <14.5 BMM MAY 18.931 13.1 PYG MAY 17.9438 14.3 BMM MAY 19.0896 13.7 BRJ ---------------------------------------------------------------------------- We thank the following contributors for the data that they have provided for this News Flash: BMM - M. Biesmans, Belgium PYG - G. Poyner, England BRJ - J. Bortle, USA SRX - R. Stubbings, Australia HSG - G. Hanson, 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! Kerriann Malatesta, Technical Assistant on behalf of Janet A. Mattei, Director ____________________________________________________________________________ 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 sending a message to: observations@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 We look forward to including your observations in future editions of AAVSO NEWS FLASH! ___________________________________________________________________________