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: 0436-03 SN 1999em 1640+25 AH HER No. 520 0000+55 FI CAS 1719-35 V478 SCO November 1, 1999 0401+50 FO PER 1803+31 VAR61 HER 0547-05 CN ORI 1911-00 FO AQL 0741-12 UY PUP 1925+42 V1504 CYG 1552+72 SS UMI 2043+41 V516 CYG ---------------------------------------------------------------------------- 0436-03 SUPERNOVA 1999em IN NGC 1637 We have been informed by the Central Bureau for Astronomical Telegrams (IAU Circular 7294) that W. D. Li, on behalf of the Lick Observatory Supernova Search Team, reports the discovery of a bright supernova in NGC 1637 on October 29.44 UT at an unfiltered CCD magnitude of about 13.5, using the 0.8-m Katzman Automatice Imaging Telescope. SN 1999em was confirmed at the Beijing Astronomical Observatory (BAO) on October 20.45 UT. No star was recorded down to magnitude 19.0 at the location of the supernova on a KAIT image of the same field taken on October 20.45 UT. The position provided by K. Stanek with the F. L. Whipple Observatory (FLWO) 1.2-m telescope shows the supernova located at: R.A. = 04h 41m 27.05s Decl. = -02deg 51' 45.8" (2000) and about 15.4" west and 17.0" south of the nucleus of NGC 1637 (IAU Circular 7296). For more information and a chart please see AAVSO Alert Notice 263, which will be posted on the AAVSO web page (www.aavso.org) shortly. ---------------------------------------------------------------------------- 0000+55 FI CASSIOPEIAE The dwarf nova type (SS CYG subclass) cataclysmic variable FI CAS appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials OCT 28.340 17.4 CCDV OCN NOV 01.290 15.5 CCDV OCN ---------------------------------------------------------------------------- 0401+50 FO PERSEI The dwarf nova type cataclysmic variable FO PER appears to be in outburst, as indicated by the following observation: AAVSO Observer UT Mag. Initials NOV 01.409 15.5 CCDV OCN According to the AAVSO International Database this star is fainter than visual magnitude 16.5 during quiescence. ---------------------------------------------------------------------------- 0547-05 CN ORIONIS The dwarf nova type (Z CAM subclass) cataclysmic variable CN ORI is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials OCT 28.362 14.2 CCDV OCN NOV 01.5361 12.6 SRX NOV 01.338 13.6 CCDV OCN ---------------------------------------------------------------------------- 0741-12 UY PUPPIS The dwarf nova type (possible Z CAM subclass) cataclysmic variable UY PUP is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials OCT 28.388 15.6 CCDV OCN NOV 01.6375 13.6 SRX NOV 01.375 13.2 CCDV OCN ---------------------------------------------------------------------------- 1552+72 SS URSAE MINORIS The dwarf nova type (SU UMA subclass) cataclysmic variable SS UMI may be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials OCT 25.804 <15.0 PYG OCT 30.7639 14.8: DPV OCT 26.7639 <13.2 DPV ---------------------------------------------------------------------------- 1640+25 AH HERCULIS The dwarf nova type (Z CAM subclass) cataclysmic variable AH HER is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials OCT 28.7396 14.5: DPV OCT 31.735 13.1 MUY OCT 30.7222 12.9 DPV ---------------------------------------------------------------------------- 1719-35 V478 SCORPII The dwarf nova type cataclysmic variable V478 SCO appears to be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials OCT 30.4306 14.4 SRX OCT 31.4396 14.4 SRX According to the AAVSO International Database this star is fainter than visual magnitude 15.0 during quiescence. ---------------------------------------------------------------------------- 1803+31 VAR61 HERCULIS The cataclysmic variable VAR61 HER is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials OCT 27.7750 <15.9 JCN OCT 31.7639 13.7 JCN OCT 28.7681 <15.5 JCN OCT 31.7868 13.8 JCN OCT 30.8160 <15.5 JCN OCT 31.791 14.3: MUY ---------------------------------------------------------------------------- 1911-00 FO AQUILAE The dwarf nova type (SS CYG subclass) cataclysmic variable FO AQL is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials OCT 25.824 <14.9 PYG OCT 30.4201 13.6 SRX OCT 25.9889 13.9 BRJ NOV 01.4347 14.0 SRX OCT 28.9847 13.7 BRJ ---------------------------------------------------------------------------- 1925+42 V1504 CYGNI The dwarf nova type (SU UMA subclass) cataclysmic variable V1504 CYG is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials OCT 27.74 15.0 KTO OCT 29.747 13.8 MUY OCT 27.760 14.7: MUY OCT 30.238 14.6 CCDV OCN OCT 28.236 14.6 CCDV OCN OCT 31.753 13.9 MUY ---------------------------------------------------------------------------- 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 OCT 26.0760 16.72 CCDV ZRE OCT 29.776 13.9 MUY OCT 27.776 13.9 MUY OCT 30.2354 13.5 BTH OCT 28.250 14.0 CCDV OCN OCT 31.2049 13.6 BTH OCT 28.9917 13.8 BRJ OCT 31.778 13.8 MUY OCT 29.2194 13.7 BTH ---------------------------------------------------------------------------- We thank the following contributors for the data that they have provided for this News Flash: BRJ - J. BORTLE, USA MUY - E. MUYLLAERT, BELGIUM BTH - T. BURROWS, USA OCN - S. O'CONNOR, CANADA DPV - P. DUBOVSKY, SLOVAKIA PYG - G. POYNER, ENGLAND JCN - C. JONES, ENGLAND SRX - R. STUBBINGS, AUSTRALIA KTO - T. KINNUNEN, FINLAND 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! ____________________________________________________________________________