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 256 (April 27, 1999) 1801-27 NOVA SAGITTARII 1999 We have been informed by the Central Bureau for Astronomical Telegrams (IAU Circular 7153) that Y. and R. Kushida, Yatsugatake South Base Observatory, Japan, report the discovery by Minoru Yamamoto, Okazaki, Japan, of a nova in Sagittarius on April 25.732 UT at photovisual magnitude 8.6, using TMax 400 film with a PO-0 filter and 200-mm f/4 lens. Yamamoto reports that no object was present down to magnitude 10.6 on films taken April 11, nor on a number of films dating back to February 1997. R. and Y. Kushida report an observation made with an 0.4-m f/6.3 Schmidt-Cassegrain (+CCD without filter) of the object at CCD magnitude 7.6 on April 26.77778 UT. They also provide the following precise position: R.A. = 18h 07m 36.22s Dec. = -27 degrees 20' 13.5" (2000) W. Liller, Vina del Mar, Chile, informs us that he obtained a low-resolution CCD spectrogram on April 27.195 UT using an 0.20-m Schmidt camera (+ objective prism) that shows a nova in the early stages of development. He measured the nova at CCDV magnitude 7.95 on April 27.18 UT (comparison star SAO 186331 with Tycho V = 8.58). He also reports that a photograph taken by him on April 21.24 UT showed no new object down to V = 11.5. Additional observations reported to the AAVSO include Apr. 27.3326 UT, 7.8, C. Scovil, Stamford, CT; 27.364, 7.18: CCDV, R. Zissell, S. Hadley, MA. Observers should note that there is a Mira variable, V4006 Sgr, to the southwest of the nova. Accompanying is a CCDV image of the field of N Sgr 99 taken by R. Zissell on Apr. 27.353 UT. Also accompanying is an AAVSO preliminary "d" scale chart prepared by C. Scovil. Please use this chart to observe 1801-27 N Sgr 99, and report your observations to AAVSO Headquarters. Please be sure to indicate which comparison stars you used to make your observations. Congratulations to Minoru Yamamoto on his discovery! CHARTS AND IMAGE AVAILABLE ON AAVSO WEB AND FTP SITES Electronic copies of the AAVSO chart of N Sgr 99 and the CCDV image of N Sgr 99 mentioned in this Alert Notice, as well as the reversed versions of these charts prepared by Marc Biesmanns, are available through our web site at the following address: http://www.aavso.org These charts and the image may also be obtained directly from our FTP site: ftp.aavso.org (198.116.78.5), in /alerts/alert256) The answering machine at AAVSO Headquarters is on nights and weekends for your convenience. Please call our charge-free number (888-802-STAR = 888-802-7827) 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