Document Type
Article
Publication Date
2-10-2009
Publication Title
The Astrophysical Journal
Department
Department of Physics and Astronomy
Abstract
Optical spectra of the bright Type II-L supernova SN 1979C obtained in April 2008 with the 6.5 m Multiple Mirror Telescope are compared with archival late-time spectra to follow the evolution of its optical emission over the age range of 11-29 years. We estimate an Hα flux decrease of around 35% from 1993 to 2008 but noticeable increases in the strength of blueshifted emission of forbidden oxygen lines. While the maximum expansion of the broad ~6700 km s–1 Hα emission appears largely unchanged from 1993, we find a significant narrowing of the double-peaked emission profiles in the [O I] λλ6300, 6364 and [O II] λλ7319, 7330 lines. A comparison of late-time optical spectra of a few other Type II SNe which, like SN 1979C, exhibit bright late-time X-ray, optical, and radio emissions, suggests that blueshifted double-peaked oxygen emission profiles may be a common phenomenon. Finally, detection of a faint, broad emission bump centered around 5800 Å suggests the presence of WC-type Wolf-Rayet stars in the SN's host star cluster.
DOI
10.1088/0004-637X/692/1/839
Original Citation
Dan Milisavljevic et al 2009 ApJ 692 839
Dartmouth Digital Commons Citation
Milisavljevic, Dan; Fesen, Robert A.; Kirshner, Robert P.; and Challis, Peter, "The Evolution of Late-Time Optical Emission from Sn 1979c" (2009). Dartmouth Scholarship. 2217.
https://digitalcommons.dartmouth.edu/facoa/2217
