C. J. Peterson and N. R. Walborn, Cerro Tololo Interamerican Observatory, report that 45 A/mm image-tube spectrograms were obtained by R. Gonzalez A. and H. J. Augensen with the C.T.I.O.-Yale 100-cm reflector on Apr. 2 and 3. The spectrum corresponds to a postmaximum galactic nova, with broad emission bands and multiple violet-displaced absorption systems. The following absorption component velocities have been measured (H = averages of H-gamma and H-beta, Fe II = averages of Fe II 4924 and 5018 A): 1977 UT H (km/s) Fe II (km/s) Apr. 2.34 -1490, -1110, -660 -1450, -1100, -600 3.36 -1560, -1150, -655 -1480, -1140, -600 The most highly displaced absorption is broader than the others and may itself consist of two components with velocities -1710 and -1465 km/s in H-beta on the Apr. 3 plate. C. B. Stephenson, Warner and Swasey Observatory, writes that a 100 A/mm image-tube spectrogram taken on Apr. 12 UT by Z. Levay shows the spectrum of a fairly fast nova about two magnitudes below and past maximum. The emission lines are about 20 A wide, and the strongest absorption component of H-beta is displaced to the violet of the center of the emission by almost 30 A.
International Astronomical Union Circular
- Pub Date:
- April 1977