.po0 THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS 25 Birch Street, Cambridge, MA 02138 USA INTERNET: aavso@aavso.org Tel. 617-354-0484 FAX 617-354-0665 AAVSO ALERT NOTICE 243 (November 06, 1997) SUPERNOVA 1997dq IN NGC 3810 We have been informed by the Central Bureau for Astronomical Telegrams (IAU Circular 6770) that S. Nakano reported the discovery by Masakatsu Aoki, in Toyama, Japan, of an apparent supernova of magnitude 15.0 on seven unfiltered CCD frames taken on Nov. 2. The discovery was confirmed by Aoki on three CCD frames taken on Nov. 3. C. Scovil (Stamford, CT) reported the supernova at visual magnitude 15.1 on Nov. 6.3972 UT. The supernova is located at: R.A. = 11h 40m 55s.90 Decl. = +11 degrees 28'45".7 (equinox 2000.0) and is 43" west and 29" north of the center of NGC 3810. Spectroscopic observations obtained at Multi-Mirror Telescope on Nov. 5.5 UT and reported by S. Sha, P. Chalis, P. Garnavich, and R. Kirshner at Harvard Smithsonian Center for Astrophysics indicate it to be a Type-Ib supernova near maximum. Accompanying is an AAVSO 'e' scale Supernova Search Preliminary chart of NGC 3810, prepared by C. Scovil and showing the location of SN 1997dq. Please use this chart to observe the supernova, and report your observations of 1135+12 SN 3810 to AAVSO Headquarters, making sure you indicate which comparison stars you used. Congratulations to Masakatsu Aoki on his latest discovery! CHARTS AVAILABLE ON AAVSO FTP SITE Electronic copies of the AAVSO chart of SN 1997dq in NGC 3810 mentioned in this Alert Notice are available from our FTP site: ftp.aavso.org (198.116.78.2), in /pub/alerts/alert243 The chart may also be accessed through our Web site at the following address: http://www.aavso.org The answering machine at AAVSO Headquarters is on nights and weekends for your convenience. Please call our charge-free number (800-642-3883) to report your observations. We also encourage observers to send observations by fax to 617-354-0665 or by e-mail through the Internet to observations@aavso.org. Many thanks for your valuable astronomical contributions and your efforts. Good observing! Janet A. Mattei Director