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: 1004-69 OY CAR IN OUTBURST - EUVE No. 580 SATELLITE IS SCHEDULED TO OBSERVE February 22, 2000 IT FOR AAVSO OBSERVERS! ---------------------------------------------------------------------------- The dwarf nova type (SU UMa subtype) cataclysmic variable OY Car is in superoutburst as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials FEB 17.7340 <15.0 SRX FEB 22.4354 12.0 SRX FEB 17.773 <15.0 PEX FEB 22.4576 11.9 SRX FEB 18.4604 <13.2 SRX FEB 22.5826 11.5 PEX FEB 21.8 <12.5 OB FEB 22.795 11.5 SJX AAVSO observers around the world have been awarded 100,000 sec of EUVE satellite time (3.5 days of observing) to observe the current superoutburst of OY Car with the satellite! Thanks to the observations above, the satellite observations have started and will continue until mid-Saturday! The EUVE time, has been awarded to the observers by the Director of EUVE, from his own discretionary time, because of the vital contributions of variable star observers in the scheduling of EUVE observations of cataclysmic variables and in correlating the EUV data with optical observations. OY Car is an eclipsing dwarf nova with an eclipse period of 1hr30m54sec. The eclipse elements are: Min (Primary) Heliocentric = 2443993.553241 + 0.0631209247 E (days) A plea to our Southern Hemisphere observers -- please monitor the superoutburst of OY Car as closely as you can, particularly the superhumps (period 1hr 32 m 57sec) and the eclipses. The first predicted eclipse for Feb 23 is at 1 hr 0m 06s (VSNET) More information will be published in AAVSO Alert Notice 272, tomorrow. We sincerely thank the observers listed below for their valuable observations which alerted us to the superouburst and the superb EUVE team who started the EUVE observations within few hours of our phone call to them. OB - M. OVERBEEK, SOUTH AFRICA SJX - J. SMIT, SOUTH AFRICA PEX - A. PEARCE, AUSTRALIA SRX - R. STUBBINGS, AUSTRALIA 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! ____________________________________________________________________________