Well, the "splitters" have been beating the "lumpers" in the SN classification business lately, so there is some new terminology. Let me exercise my memory here...
Classification of Supernovae
| SN Type |
Characteristics |
Guess at Progenitor |
| Ia |
- No hydrogen in spectrum
- Strong absoption at 6550 A near max light
- Late-time spectrum iron-group emission lines
|
- White dwarf that accretes more than a Chandrasekhar mass
- Two white dwarfs that collide
|
| Ib |
- No hydrogen in spectrum
- Absorption near 5700 A, due to He (plus other He lines)
- Late-time spectrum emission from OI, CaII
|
- Massive star which has been stripped of H before core-collapse?
- Wolf-Rayet star?
|
| Ic |
- No hydrogen in spectrum
- No helium in spectrum
- Late-time spectrum emission from OI, CaII
|
- Massive star which has been stripped of H before core-collapse?
- Wolf-Rayet star?
|
| II-P |
- Hydrogen in spectrum, with P-Cyngi profile
- Light curve has plateau for 30-90 days soon after max light
|
|
| II-L |
- Hydrogen in spectrum weak or no P-Cygni profile
- Light curve falls linearly after max light
|
- Less massive supergiant?
- Lost some of envelope?
|
| IIb |
- Hydrogen in spectrum, but not much
- Helium in spectrum
- Late-time spectrum emission from OI, CaII, plus H
|
- Massive star which has lost MOST (but not all) of its H envelope (in binary?)
|
| II-n |
- Hydrogen in spectrum, with narrow emission lines on top of broad emission features
- Slow decline in light curve at late times
|
- Massive Star which sits in middle of massive stellar outflow?
|
There's also a paper in a recent A&A which suggests a new classification scheme (based primarily on light curve properties?), but it hasn't been widely adopted, as far as I know.
The old Zwicky classes (types III, IV, V) are not used at all at the current time, as far I as know.