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: 1554-22 DELTA SCO No. 651 0207-63 WX HYI 1841+37 AY LYR July 31, 2000 0814+73 Z CAM 1848+26 CY LYR 1802+31 V1008 HER 1920-10 DH AQL ---------------------------------------------------------------------------- 1554-22 DELTA SCO IN OUTBURST AND CLASSIFIED AS A Be STAR We have been informed by AAVSO observer Sebastian Otero, Buenos Aires, Argentina, and the Central Bureau for Astronomical Telegrams (IAU Circular 7461) that the spectral type B0.3 star delta Scorpii is undergoing a gamma Cas-like outburst (a gamma Cas variable is an eruptive irregular variable, usually a rapidly-rotating B star with emission lines due to outflow of matter; gamma Cas is the prototype). Otero first reported delta Sco brightening slowly from its longtime magnitude of 2.3 on June 30, and reported it at visual magnitude 2.0 by July 20. The star continues to slowly brighten, as indicated by the observations listed below. Spectroscopy of delta Sco taken on July 19.89 UT with the Skinakas Observatory 1.3-m telescope by J. Fabregat, University of Valencia, and P. Reig, Foundation for Research and Technology Hellas and University of Crete, Heraklion, showed H-alpha in emission, confirming delta Sco as a Be star, as first proposed by Cote and van Kerkwijk in 1990 (IAU Circular 7461). Photometry is strongly recommended for this star, using omega-1 Sco (V = 3.93, Johnson V magnitude from Hipparcos and Tycho Catalogue) as a comparison star and SAO 183916 (HIP 77911, GSC 67792142, V = 6.86, Johnson V magnitude from Hipparcos and Tycho Catalogue) as a check star. Visual observations are also recommended, using alpha Lupi (magnitude 2.3) and gamma Cen (magnitude 2.2) as comparison stars. An AAVSO preliminary chart for delta Sco is being prepared and will be posted on the AAVSO website. Please monitor this star closely and report your observations to AAVSO Headquarters, being sure to indicate the comparison stars you used. Congratulations to Sebastian for detecting this very small-amplitude visual outburst of delta Sco! AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUN 30.03 2.24 OSE (via IAU Circular 7461) JUL 04.0778 2.2 OSE JUL 24.0236 1.9 OSE JUL 16.9285 2.1 OSE JUL 24.134 1.9 MRV JUL 16.9292 2.1 OSE JUL 24.87 1.9 RMQ JUL 16.9306 2.1 OSE JUL 25.0479 1.9 OSE JUL 17.1236 2.0 OSE JUL 25.56 1.8 FMX JUL 17.1243 2.1 OSE JUL 25.85 1.8 RMQ JUL 18.9500 2.1 OSE JUL 26.885 1.9 MUY JUL 20.0181 2.0 OSE JUL 26.90 1.9 GGX JUL 21.899 1.9 LTO JUL 27.4132 1.8 BQT JUL 22.42 2.0 FMX JUL 27.85 1.8 RMQ JUL 22.5150 1.9 BQT JUL 28.881 1.9 MUY JUL 22.951 2.0 LTO JUL 28.89 1.9 GGX JUL 23.1201 1.9 OSE JUL 29.5528 1.7 SSU JUL 23.163 1.9 MRV JUL 30.4674 1.7 SSU JUL 23.85 1.9 RMQ JUL 30.48 1.7: FMX JUL 23.934 1.8 LTO JUL 30.9597 1.9 OSE ---------------------------------------------------------------------------- 0207-63 WX HYDRI The dwarf nova type (SU UMA subclass) cataclysmic variable WX HYI appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUL 28.540 15.0 SRX JUL 31.472 12.5 SRX ---------------------------------------------------------------------------- 0814+73 Z CAMELOPARDALIS The dwarf nova type (Z CAM subclass prototype) cataclysmic variable Z CAM appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUL 25.903 13.1 RMQ JUL 29.00 10.1 GUN ---------------------------------------------------------------------------- 1802+31 V1008 HERCULIS The dwarf nova type cataclysmic variable V1008 HER is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUL 21.947 <15.5 PYG JUL 29.9306 13.0 JCN JUL 25.1840 <14.9 SXN JUL 29.983 13.5 MUY JUL 26.898 <14.2 MUY JUL 30.928 13.5 SPK ---------------------------------------------------------------------------- 1841+37 AY LYRAE The dwarf nova type (SU UMA subclass) cataclysmic variable AY LYR is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUL 27.912 <15.5 RMQ JUL 30.89 13.7 VET JUL 27.9507 <14.2 DPV JUL 30.899 13.2 MUY JUL 29.90 <14.5 GUN JUL 30.901 13.4 OJR JUL 29.9444 <15.3 JCN JUL 30.93 13.5 VET JUL 30.3146 13.9 LMK JUL 30.98 13.1 GUN JUL 30.5514 13.6 SSU JUL 31.2326 13.4 KB ---------------------------------------------------------------------------- 1848+26 CY LYRAE The dwarf nova type cataclysmic variable CY LYR is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUL 27.913 <15.0 RMQ JUL 30.07 13.3 VET JUL 28.90 15.0 VET JUL 30.89 13.3 VET JUL 29.00 <14.2 GUN JUL 30.901 13.4 MUY JUL 29.90 13.0 GUN JUL 30.904 13.4 OJR ---------------------------------------------------------------------------- 1920-10 DH AQUILAE The dwarf nova type (SU UMA subclass) cataclysmic variable DH AQL appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUL 28.554 <15.0 SRX JUL 31.499 12.6 SRX JUL 31.466 12.6 SRX ---------------------------------------------------------------------------- We thank the following contributors for the data that they have provided for this News Flash: BQT - A. BERESFORD, AUSTRALIA MUY - E. MUYLLAERT, BELGIUM DPV - P. DUBOVSKY, SLOVAKIA OJR - J. OSORIO, SPAIN FMX - F. FARRELL, AUSTRALIA OSE - S. OTERO, ARGENTINA GGX - G. GUZMAN, FRANCE PYG - G. POYNER, ENGLAND GUN - J. GUNTHER, FRANCE RMQ - M. RESZELSKI, POLAND JCN - C. JONES, ENGLAND SPK - P. SCHMEER, GERMANY KB - W. KAMINSKI, USA SRX - R. STUBBINGS, AUSTRALIA LMK - M. LINNOLT, USA SSU - S. SAKUMA, JAPAN LTO - T. LANGE, GERMANY SXN - M. SIMONSEN, USA MRV - R. MODIC, USA VET - M. VERDENET, FRANCE 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! ____________________________________________________________________________