Observations of SN 1986J in NGC 891
Abstract
Supernova SN 1986J was discovered at radio wavelengths with the VLA. The object is currently strongest at 6 cm wavelength and probably turned on at 6 cm wavelength in early 1984 and at 20 cm wavelength one or two years later. H I absorption-line observations show that the SN is about 7.7 kpc from the center and within 170 pc of the plane of NGC 891. SN 1986J is, in the radio, both the brightest and most luminous supernova yet found.The supernova has been identified optically with a 20th-magnitude (September, 1986) point source in NGC 891, and was approximately 1 mag brighter in January, 1984. The spectrum is dominated by emission lines; H I, He I, forbidden O I, and probably Fe I and Fe II are seen. The Balmer decrement is very large, with an H-alpha/H-beta flux ratio of about 60. The He I line spectrum and the current optical brightness both suggest that only a small amount of this decrement can be attributed to extinction. The spectrum is similar to those seen in the late phases of type II supernovae; however, the small linewidth (FWHM of about 1000 km/s) suggests that SN 1986J is actually type V.
- Publication:
-
The Astronomical Journal
- Pub Date:
- July 1987
- DOI:
- 10.1086/114447
- Bibcode:
- 1987AJ.....94...61R
- Keywords:
-
- Radio Spectra;
- Stellar Spectrophotometry;
- Supernovae;
- Absorption Spectra;
- Emission Spectra;
- Spectral Line Width;
- Stellar Luminosity;
- Very Large Array (Vla);
- Astrophysics;
- STARS: SUPERNOVAE