Circular No. 3206 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. Cable Address: SATELLITES, NEWYORK Telex: 921428 Telephone: (617) 864-5758 HEAO-1 OBSERVATIONS G. J. Fishman writes: "The HEAO-1 spacecraft continues to operate very well. Pointed observations are being made about 4 to 5 times per week for 3 to 6 hours. At all other times the spacecraft will be in its normal scanning mode: 90o from the sun with a rotation period of ~ 35 min. The latest pointing information may be obtained from one of the HEAO-1 investigators or from me at the address: NASA Headquarters, Code SC-7, Washington, DC 20546, U.S.A. (telephone 202-755-3616). Upcoming objects for which simultaneous optical and radio coverage would be desirable include AM Her (Apr. l8d06h00m-18d12h00m UT) and YZ CMi (Apr. 20d14h00m-20d20h00m UT)." NOVA IN LARGE MAGELLANIC CLOUD J. A. Graham, Cerro Tololo Interamerican Observatory, reports: "The probable nova (IAUC 3204) has been confirmed. The spectrum on the discovery plate, taken by H. Rojas on Mar. 29.0 UT, appears normal for a nova several days past maximum. The B magnitude on this plate is estimated to be 13.0 +/- 0.2. Photoelectric photometry by A. Landolt gives the preliminary values: Mar. 30.050 UT, V = 13.35, B-V = -0.03, U-B = -0.73; Apr. 1.021, 14.51, -0.24, -0.80; a direct plate taken on Apr. 2.0 by Landolt indicates V ~ 15.0. A Curtis Schmidt survey plate (with objective prism, dispersion 300 A/mm) taken on Mar. 17.0 shows at the position of the nova faint but very definite emission lines superposed on a barely detectable continuous spectrum that corresponds to a B magnitude of about 15. Narrow emission lines of H-beta, H-gamma and H-delta are identified at this premaximum phase, as is a broad feature near 4680 A. Neither the emission lines nor the continuum are seen on earlier plates of the region. Observations currently available suggest that the nova reached maximum on Mar. 19 or 20 at magnitude 10 and that the decline has been very fast, averaging 0.5 magnitude per day. Further observations would be extremely useful for a definitive interpretation." NOVA SERPENTIS 1978 J. Mattei, American Association of Variable Star Observers, communicates the following visual magnitude estimates, by J. Morgan, Prescott, Arizona, derived with respect to a preliminary AAVSO sequence: Mar. 25.51 UT, 9.4; 26.53, 9.5; 27.51, 9.4; 28.49, 9.6; 29.51, 9.5; 30.51, 9.0; 31.48, 9.8; Apr. 3.51, 10.0. 1978 April 10 (3206) Brian G. Marsden
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