THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS 25 Birch Street, Cambridge, MA 02138 USA Tel. 617-354-0484 Fax 617-354-0665 INTERNET: aavso@aavso.org * * * AAVSO NEWS FLASH * * * Subject: SN 1998bu, V373 Cen, V436 Cen, No. 297 V442 Cen, IR Gem, SU UMa, SS UMi May 11, 1998 ____________________________________________________________________________ SUPERNOVA 1998bu IN NGC 3368 (=M96) We have been informed by Mirko Villi, Italy, and by the Central Bureau for Astronomical Telegrams (IAU Circular 6899) of Villi's discovery of an apparent supernova in NGC 3368. Unfiltered CCD images taken by Villi on May 9.9 UT showed the supernova at approximate magnitude 13.0. The supernova is located at: R.A. = 10h 46m 46.03s Decl. = +11 degrees 50' 07.1" (equinox 2000.0) which is 4.3" east and 55.3" north of the center of NGC 3368. For more information on this discovery please see AAVSO Alert Notice 249. This Alert Notice and a chart for SN 1998bu are available from our FTP site: ftp.aavso.org (198.116.78.2), in /pub/alerts/alert249/ This information may also be accessed through our Web site at the following address: http://www.aavso.org We congratulate Mirko Villi on his most recent discovery! ----------------------------------------------------------------------------- V373 CENTAURI The dwarf nova type cataclysmic variable V373 Cen appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials MAY 01.4410 15.0 SRX MAY 04.4167 14.4 SRX MAY 02.4215 14.8 SRX MAY 08.5347 13.5 SRX ----------------------------------------------------------------------------- V436 CENTAURI The dwarf nova type (SU UMa subclass) cataclysmic variable V436 Cen is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials MAY 09.698 <13.7 MLF MAY 11.696 11.5 MLF MAY 10.7 <13.2 OB MAY 11.708 12.0 OB ----------------------------------------------------------------------------- V442 CENTAURI The dwarf nova type (SS Cyg subclass) cataclysmic variable V442 Cen is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials MAY 04.4111 <14.4 SRX MAY 10.721 11.8 MLF MAY 08.4250 12.0 SRX MAY 11.694 11.9 MLF MAY 09.697 11.8 MLF ----------------------------------------------------------------------------- IR GEMINORUM The dwarf nova type (SU UMa subclass) cataclysmic variable IR Gem appears to be in outburst, as indicated by the following observations: AAVSO Observer UT Mag. Initials APR 30.0610 15.77 CCDV ZRE MAY 10.100 12.5 MRV ----------------------------------------------------------------------------- SU URSAE MAJORIS The dwarf nova type (SU UMa subclass prototype) cataclysmic variable SU UMa is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials MAY 03.894 14.4 PYG MAY 08.99 12.0 GRL MAY 05.3917 <14.0 HSG MAY 9.908 12.8 PYG ----------------------------------------------------------------------------- SS URSAE MINORIS The dwarf nova type (SU UMa subclass) cataclysmic variable SS UMi appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials MAY 05.4042 <15.8 HSG MAY 09.991 14.4 PYG MAY 07.4299 <14.7 HSG MAY 10.103 14.1 PYG ----------------------------------------------------------------------------- We thank the following contributors for the data that they have provided for this News Flash: GRL - B. Granslo, Norway HSG - G. Hanson, USA MLF - B. Monard, South Africa MRV - R. Modic, USA OB - D. Overbeek, South Africa PYG - G. Poyner, England SRX - R. Stubbings, Australia 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 ____________________________________________________________________________ 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 sending a message to: observations@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 We look forward to including your observations in future editions of AAVSO NEWS FLASH! ____________________________________________________________________________