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: REMINDER: CHANDRA TO OBSERVE U GEM IN OUTBURST No. 1083 0524-03 V1159 ORI 2053+25 VW VUL December 19, 2002 2023+43 V503 CYG ---------------------------------------------------------------------------- REMINDER: CHANDRA TO OBSERVE U GEM IN OUTBURST As mentioned in News Flash No. 1069, our colleagues from Lawrence Livermore National Laboratory and the Space Telescope Science Institute will be observing U Gem during its next outburst with Chandra's High Energy Transmission Grating Spectrometer (HETGS) and Chandra's Low Energy Transmission Grating Spectrometer (LETGS) to measure the soft and hard x-rays at maximum and a few days after maximum. It has already been over 200 days since the last recorded outburst of U Gem in late May, 2002. This is well over the object's average outburst interval of 124 days. Therefore, we expect U Gem to have an outburst in the very near future. Observers are encouraged to keep a close eye on U Gem leading up to and continuing throughout the next outburst. Please notify HQ when U Gem brightens to at least 13.0 magnitudes so that we can inform our colleagues and they in turn can trigger the Chandra observations. Continuing coverage during the outburst is also very important so that we may be able to keep our colleagues updated. ---------------------------------------------------------------------------- 0524-03 V1159 ORIONIS The dwarf nova type (SU UMA subclass) cataclysmic variable V1159 ORI appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 17.4646 <14.3 LMK DEC 19.4826 13.5 LMK DEC 17.4920 <13.6 SRX ---------------------------------------------------------------------------- 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 observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 13.7595 17.2 CCD DRG DEC 18.7960 14.0 PYG DEC 14.2993 <14.5 LMK ---------------------------------------------------------------------------- 2053+25 VW VULPECULAE The dwarf nova type cataclysmic variable VW VUL appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 09.7920 15.1 PYG DEC 18.7820 13.8 PYG DEC 13.7414 15.11 CCD DRG ---------------------------------------------------------------------------- We thank the following contributors for the data that they have provided for this News Flash: DRG - R. DIETHELM, SWITZERLAND PYG - G. POYNER, ENGLAND LMK - M. LINNOLT, USA SRX - R. STUBBINGS, AUSTRALIA 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! ____________________________________________________________________________