G. de Vaucouleurs, University of Texas, writes that provisional reductions of visual observations made by him with the 30-cm finder of the 205-cm reflector at the McDonald Observatory and of photoelectric observations by B. Smith and B. Beardsley with the 75-cm reflector yield the following: 1979 UT mv V B-V U-B Apr. 23.2 12.08 12.05 +0.10 -0.49 24.2 12.14 12.09 +0.12 -0.45 25.2 12.03 26.2 12.4: The supernova is very blue in U-B and apparently unobscured, corresponding to Pskovskij's (1977, Soviet Astron. 21, 675) beta class 10 at or near maximum. The observed value B = 12.2 at maximum is consistent with the characteristic M_B = -18.5 for type I supernovae at maximum if the Virgo S cloud modulus is B - A_B - M_B = 30.5 and A_B = 0.2 (Astrophys. J. 1979, 227, 729). The three previously recorded supernovae in this galaxy, 1901B, 1914A and 1959E, were of magnitudes 15.6, 15.7 and 17.5 at maximum, respectively. G. F. O. Schnur, European Southern Observatory, informs us that his observations on IAUC 3351 refer to the wrong star and should therefore be ignored.
International Astronomical Union Circular
- Pub Date:
- May 1979