Supernova 2001ig in NGC 7424
Abstract
M. M. Phillips, Observatories of the Carnegie Institute of Washington (OCIW); and N. B. Suntzeff, Cerro Tololo Interamerican Observatory (CTIO), report that SN 2001ig was observed by Suntzeff and K. Krisciunas (CTIO) with the facility CCD imager on the 1.5-m CTIO telescope, yielding the following photometry: Dec. 12.1 UT, V = 14.26, B-V = -0.05; Dec. 13.0, V = 14.24. Spectroscopic observations were obtained by R. Carlberg (University of Toronto) on Dec. 11 and by M. Gladders (OCIW) and F. Barrientos (Pontificia Universidad Catolica de Chile) on Dec. 13 with the 6.5-m Baade Telescope at Las Campanas Observatory; these data were reduced by T. Matheson and S. Jha (Harvard-Smithsonian Center for Astrophysics). The first of these spectra shows only a few broad absorption features at 400, 425, 460, and 525 nm, and it defies simple classification. The Dec. 13 spectrum shows a broad P-Cyg feature with a peak at about 650 nm and blue-shifted absorption at 612 nm. Also visible are broad absorption features at 408, 458, and 556 nm. The general aspect of this spectrum is similar to early spectra obtained of the type-IIb supernova 1987K (see Filippenko 1988, A.J. 96, 1941), although SN 2001ig is much bluer. If this is true, the P-Cyg feature would be H-alpha, and the other absorptions would correspond to H-gamma, H-beta, and He I 587.6-nm at expansion velocities of 15 000-20 000 km/s. However, further spectroscopy will be needed to confirm these provisional identifications.
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- December 2001
- Bibcode:
- 2001IAUC.7772....2P