THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS 25 Birch Street, Cambridge, MA 02138 USA BITNET: aavso@cfa SPAN: cfa::aavso INTERNET: aavso@cfa.harvard.edu Tel. 617-354-0484 FAX 617-354-0665 AAVSO ALERT NOTICE 189 (August 1, 1994) 1157+62 SUPERNOVA 1994W IN NGC 4041 We have been informed by the Central Bureau for Astronomical Telegrams (IAU Circ. 6042) of the visual discovery of a supernova in NGC 4041 by G. Cortmi and M. Villi, Valbura, Italy, on July 29.85 UT at about magnitude 13.5. The 1950 position of NGC 4041 is: RA = llh 59.6m Dec = +62deg 25' The object was not seen down to limiting magnitude 14.5 on July 11.8 UT. R. Barbon and U. Munari at Asiago Astrophysical Observatory and A. Bragaglia at Bologna Astronomical Observatory (BAO) confirm the supernova on their CCD images of July 30.9 UT, and report that SN 1994W is on an arm of the galaxy and is located 18" north, 9" west of the nucleus. C. Pollas and L. Zongli also confirm the existence of the supernova on a panchromatic film obtained on July 30.90 UT at Observatoire de la Cote d'Azur. C. Pollas provides the following accurate position for SN 1994W: R.A. = 11h 59m 37.67s Dec = +62deg 25' 14".6 (epoch 1950) with a corresponding offset from the center of the galaxy of 7".8 west and 17".5 north, and a photovisual brightness of about 14 (IAU Cim. 6043). C. E. Spratt, Victoria, British Columbia, Canada, estimated the brightness of the supernova to be at magnitude 13.4 on August 31.261 UT by extrapolating from the AAVSO "d" chart of RS UMa (1234 + 59) using the 13.5 and 13.2 comparison stars m that field. Accompanying is a section from the AAYSO Variable Star Atlas showing the galaxy and the position of the supernova and also the "d" chart of RS UMa to help extrapolate the magnitude of the supernova until a chart of the supernova field containing the comparison star sequence is available. Please monitor this supernova and report your observations to Headquarters, indicating the comparison stars you have used in making our estimate. The answering machine at Headquarters, with our charge free number 1-800-b42-3883), is on nights and weekends for your convenience. Our congratulations to G. Cortini and M. Villi on their visual discovery of Supernova 1994W in NGC 4041! Many thanks for your efforts and valuable astronomical contributions. Good observing! Janet A. Mattei Director