Circular No. 4816 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. Telephone 617-495-7244/7440/7444 (for emergency use only) TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505 MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN PERIODIC COMET BRORSEN-METCALF (1989o) A. Schultz, U. Fink and M. DiSanti, University of Arizona, report that spectra obtained on July 13.46 UT with the 1.54-m Catalina reflector and the LPL CCD and spectrograph system showed emissions of C2, NH2, O I[1D], H2O+ and CN, as well as a weak continuum with flat albedo. The C2 emission strengths were comparable to those of P/Halley, but NH2 was down. The ratio of O I emission to continuum integrated over 60" along the slit at 630 nm was 6.9. (This ratio for P/Halley was 0.95 at the same heliocentric distance.) The O I 630-nm luminosity was measured as 1.52 x 10**27 photon/s. This translates into a production rate for H2O of 2.46 x 10**28 s-1, which is a factor of 7.0 smaller than was measured for P/Halley at the same heliocentric distance (1.36 AU) before perihelion. mu CENTAURI G. J. Peters, Space Sciences Center, University of Southern California, communicates: "An H-alpha spectrum of mu Cen taken on June 13 with the coude feed telescope + TI3 CCD detector at Kitt Peak National Observatory during a 'request night' reveals that the emission outburst reported by J. C. Bhattacharyya et al. (IAUC 4806) was well underway by mid-June. The double H-alpha emission feature observed with a peak intensity of 1.2 Icont (V/R about 1.7) clearly establishes this as the strongest outburst since those of 1980 and 1983-84 (cf. Peters 1986, Ap.J. 301, L61 and references therein) and further observations are urged." V404 CYGNI R. D. Gehrz, J. Johnson and T. Harrison, University of Minnesota, report that observations on July 20.42 UT with the Minnesota InSb photometer on the Wyoming 2.34-m infrared telescope gave J = 11.21, H = 10.21, K = 9.44, L' = 8.03 (uncertainty 0.05 mag in each case). SUPERNOVA 1989B IN NGC 3627 Further visual magnitude estimates: Apr. 24.1 UT, 15.6 (T. Martinez, Cleveland, MO); May 1.88, 15.0 (M. Verdenet, Bourbon-Lancy, France); 4.88, 15.6: (S. Korth, Dusseldorf, West Germany); 6.4, 15.7 (S. H. Lucas, Mansfield, OH); 7.25, 15.5 (B. Archinal, Mansfield, OH); 8.1, 15.7 (Martinez); June 7.09, 16.0 (R. Bunge, Mansfield, OH). 1989 July 21 (4816) Brian G. Marsden
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