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: 1247-28 EX HYA No. 623 0803+62 SU UMA May 18, 2000 0814+73 Z CAM ---------------------------------------------------------------------------- 1247-28 EX HYDRAE - MULTIWAVELENGTH OBSERVING CAMPAIGN CONTINUES As announced in AAVSO Alert Notice 272 and AAVSO News Flash No. 613 a multi-wavelength, multi-satellite campaign is underway on EX Hya. EUVE continues to observe this star and we have been informed that the FUSE satellite will observe EX Hya May 18-20. Good optical coverage during this campaign is essential to the success of this program. Please monitor EX Hya very closely from now through the end of June. Both visual and CCD observers are encouraged to observe EX Hya every 5 minutes for as long as possible. For those CCD observers interested in carrying out multi-color CCD observations we are including photoelectric comparison star magnitudes in B and V, which were published by Karen Meech in PASP, Vol 95, No 571, Pg 662. ==================================== AAVSO e chart V B magnitude Comp.star 114 11.35 12.22 120 12.02 12.96 122 12.17 12.77 127 12.70 13.88 129 12.89 14.18 135 13.48 14.12 ==================================== An "e" scale AAVSO preliminary chart of EX Hya is available through the AAVSO web page at the following address: http://www.aavso.org/alerts/alert272/ Please be sure to indicate which comparison stars you used to make your estimates when you report your observations. Your participation is essential to the success of this ground-breaking observing campaign! ---------------------------------------------------------------------------- 0803+62 SU URSAE MAJORIS The dwarf nova type (SU UMA subclass prototype) cataclysmic variable SU UMA appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials MAY 16.978 13.9 RMQ MAY 18.2069 11.8 HSG MAY 17.0958 13.94 CCDV GKA ---------------------------------------------------------------------------- 0814+73 Z CAMELOPARDALIS The dwarf nova type (Z CAM subclass prototype) cataclysmic variable Z CAM is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials MAY 15.9790 13.2: SJZ MAY 18.2097 11.8 HSG MAY 16.898 13.4 RMQ MAY 18.2104 11.4 BTH ---------------------------------------------------------------------------- We thank the following contributors for the data that they have provided for this News Flash: BTH - T. BURROWS, USA RMQ - M. RESZELSKI, POLAND GKA - K. GRAHAM, USA SJZ - J. SPEIL, POLAND HSG - G. HANSON II, 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! ____________________________________________________________________________