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."
International Astronomical Union Circular
- Pub Date:
- April 1978