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: 0324+43 GK PER 0625+17 OW GEM No. 890 0055+42 IW AND 1640+25 AH HER December 21, 2001 0058+40 RX AND 1920+52 V1113 CYG 0109+37 FO AND 2043+41 V516 CYG 0641+28 IR GEM 2209+12 RU PEG ---------------------------------------------------------------------------- PLEASE NOTE: NO NEWS FLASHES FROM DECEMBER 24, 2001 TO JANUARY 2, 2002 Because of staff vacations scheduled during the holiday season, AAVSO Headquarters will be operating with a significantly reduced staff from Monday, December 24, 2001 to Wednesday, January 02, 2002. No News Flashes will be issued during this time (unless extraordinary circumstances arise such as a discovery a nova and/or a bright supernova, very unusual behavior of a variable star, etc.). The Quick Look files on our website, containing the most recent nightly reported observations, will be updated regularly. All of us at AAVSO Headquarters wish you and your loved ones a Happy Holiday Season and a very Happy New Year! ---------------------------------------------------------------------------- 0324+43 GK PERSEI - Observing Campaign Astronomers at Livermore National Laboratory in California and NASA Goddard Space Flight Center are preparing for Target of Opportunity Observations (TOO) of GK Per - the 1901 nova, classified as a magnetic cataclysmic variable of intermediate polar subclass - during its next outburst with the Chandra and XMM X-ray satellites. GK Per has a quasi-periodic outburst interval ranging from 900 to 1300 days. The most recent outburst of GK Per began in late February, 1999. The star reached a maximum mean magnitude of 10.5 about 1 month later. Based on the interval between the most recent 2 outbursts (approximately 1,100 days) we would expect the next outburst to occur in the next several months. GK Per was featured on the AAVSO web page as the Variable Star of the Month in November 2000. For more information please see the following page: http://www.aavso.org/vstar/vsotm/1100.stm Please keep a very close eye on this variable and inform us when it starts to brighten -- 12.5 or brighter in magnitude. Immediate notification of the star's brightening and good coverage throughout the next outburst are extremely important for the triggering of the satellite observations and for correlation with the satellite data. ---------------------------------------------------------------------------- 0625+17 OW GEMINORUM The bright - 8.2 magnitude - eclipsing binary OW Gem will begin its rare, long eclipse late this month with a minimum occuring in early January. Although the period of the eclipses are 3.5 years, due to the conjuntion of Gemini with the Sun the eclipses have been only observable every 7 years since discovery in 1988. The eclipse will be especially long, lasting over a week with predicted fading of 1.8 magnitudes. Secondary eclipses may also be detectable with CCD equipment. Normal and reversed C & F-scale (w/ccd info) charts for OW Gem are available at the URL below: http://charts.aavso.org/PRELIM/GEM/OW_GEM/ If you would like to observe this eclipse, please observe OW Gem once or twice a night beginning at the end of next week and lasting until it has recovered. Observations can be sent to AAVSO HQ on this eclipsing binary star using the regular AAVSO format for reporting observations and we will relay them to the eclipsing binary committee chair, Marvin Baldwin. OW Gem was discovered to be an eclipsing binary star by our current President Dan Kaiser in 1988. For more information on this object visit the AAVSO Discussion Group at the URL below. It includes references to other publications. http://mailman.McMaster.CA/mailman/private/aavso-discussion/0112/msg00020.html You may also visit IBVS 3196 for more info. ---------------------------------------------------------------------------- 0055+42 IW ANDROMEDAE The variable IW AND appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 19.0902 <14.7 SXN DEC 21.1631 14.4 SXN DEC 20.9221 <15.5 RMQ ---------------------------------------------------------------------------- 0058+40 RX ANDROMEDAE The dwarf nova type (Z CAM subclass) cataclysmic variable RX AND is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 20.1000 14.1 CGF DEC 21.1519 10.8 AAP DEC 20.9229 11.7 RMQ DEC 21.1617 11.1 SXN ---------------------------------------------------------------------------- 0109+37 FO ANDROMEDAE The dwarf nova type (SU UMA subclass) cataclysmic variable FO AND may be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 19.0520 17.42 CCDV ZRE DEC 20.9235 15.9: RMQ DEC 19.0839 <14.7 SXN DEC 21.1513 <14.0 SXN DEC 20.1000 <14.7 CGF ---------------------------------------------------------------------------- 0641+28 IR GEMINORUM The dwarf nova type (SU UMA subclass) cataclysmic variable IR GEM may be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 12.2230 16.33 CCDV ZRE DEC 20.0825 14.5: RMQ DEC 13.9270 <15.0 RMQ DEC 20.8117 <14.7 RMQ DEC 18.2160 <13.4 SRB DEC 21.3173 <13.6 LMK DEC 19.2207 <14.2 SXN ---------------------------------------------------------------------------- 1640+25 AH HERCULIS The dwarf nova type (Z CAM subclass) cataclysmic variable AH HER appears to be in outburst, as indicated by the following observation: AAVSO Observer UT Mag. Initials DEC 18.2083 12.0 GUN ---------------------------------------------------------------------------- 1920+52 V1113 CYGNI The dwarf nova type (SS CYG subclass) cataclysmic variable V1113 CYG may be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 10.7568 <15.6 JCN DEC 19.0208 <14.0 SXN DEC 12.0068 <14.0 SXN DEC 20.7507 15.8: RMQ DEC 13.7228 <14.5 RMQ ---------------------------------------------------------------------------- 2043+41 V516 CYGNI The dwarf nova type (SS CYG subclass) cataclysmic variable V516 CYG is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 18.9868 <15.5 TDB DEC 20.0 <14.2 CGF DEC 19.0 <14.2 CGF DEC 20.7555 14.2 RMQ DEC 19.0298 <14.2 SXN DEC 20.9799 14.3 TDB ---------------------------------------------------------------------------- 2209+12 RU PEGASI The dwarf nova type (SS CYG subclass) cataclysmic variable RU PEG is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials DEC 18.1019 12.4 AAP DEC 20.0424 12.1 CGF DEC 19.0 12.4 CGF DEC 20.8020 12.1 RMQ DEC 19.0479 12.4 SXN DEC 21.1298 11.2 AAP ---------------------------------------------------------------------------- We thank the following contributors for the data that they have provided for this News Flash: AAP - A. ABBOTT, CANADA RMQ - M. RESZELSKI, POLAND CGF - G. CHAPLE JR., USA SRB - R. STINE, USA GUN - J. GUNTHER, FRANCE SXN - M. SIMONSEN, USA JCN - C. JONES, ENGLAND TDB - D. TAYLOR, CANADA LMK - M. LINNOLT, 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! 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! ____________________________________________________________________________