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 1920+52 V1113 CYG No. 429 0803+62 SU UMA 2023+43 V503 CYG April 28, 1999 1454+41 TT BOO 2043+41 V516 CYG ---------------------------------------------------------------------------- REQUEST TO MONITOR 2138+43 SS CYGNI FOR MULTIWAVELENGTH OBSERVATIONS We are collaborating with astronomers from Lawrence Livermore National Laboratory in the scheduling of multiwavelength observations of SS Cyg in outburst. This observing run will involve the Hubble Space Telescope (HST), the Rosse X-Ray Timing Explorer (RXTE), and possibly the Extreme Ultraviolet Explorer (EUVE). In this year's campaign, the investigating astronomers have requested that we inform them immediately when SS Cyg starts to go into outburst and continue to keep them informed throughout the outburst. Please monitor SS Cyg closely, and inform us immediately by phone, fax, or email when it becomes brighter than 11.5. Once SS Cyg goes into outburst, please send your observations to us daily. For more information on this observing campaign, please see AAVSO Alert Notice 257, which will be published and posted on the AAVSO web site tomorrow. (http://www.aavso.org) ---------------------------------------------------------------------------- 0803+62 SU URSAE MAJORIS The dwarf nova type (SU UMA subclass prototype) cataclysmic variable SU UMA is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials APR 24.897 14.1 PYG APR 27.9021 11.9 JCN APR 25.0979 <12.7 MDP APR 27.904 12.5 PYG APR 27.0708 <13.4 MDP APR 28.0903 12.0 MDP APR 27.862 12.3 MUY ---------------------------------------------------------------------------- 1454+41 TT BOOTIS The dwarf nova type (SU UMA subclass) cataclysmic variable TT BOO is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials APR 25.054 <14.8 PYG APR 28.03 <13.7 KTO APR 27.924 13.7 PYG APR 28.063 13.8 PYG ---------------------------------------------------------------------------- 1920+52 V1113 CYGNI The dwarf nova type (SS CYG subclass) cataclysmic variable V1113 CYG appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials APR 10.985 <15.6 PYG APR 28.033 13.9 PYG APR 25.115 <14.3 PYG ---------------------------------------------------------------------------- 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 observation: AAVSO Observer UT Mag. Initials APR 28.2930 14.57 CCDV ZRE ---------------------------------------------------------------------------- 2043+41 V516 CYGNI The dwarf nova type (SS CYG subclass) cataclysmic variable V516 CYG appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials APR 19.3500 17.38 CCDV ZRE APR 28.3500 15.65 CCDV ZRE APR 28.052 <14.2 PYG ---------------------------------------------------------------------------- We thank the following contributors for the data that they have provided for this News Flash: JA - A. JONES, NEW ZEALAND PYG - G. POYNER, ENGLAND JCN - C. JONES, ENGLAND SCE - C. SCOVIL, USA KTO - T. KINNUNEN, FINLAND SPK - P. SCHMEER, GERMANY LIW - W. LILLER, CHILE SQN - L. SHAW, USA MDP - P. MCDONALD, CANADA ZRE - R. ZISSELL, USA MUY - E. MUYLLAERT, BELGIUM 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! ____________________________________________________________________________