Smartt, S. J. (2009). Progenitors of Core-Collapse Supernovae. doi: /annurev-astro

Supernovae are primarily classified by the appearance of their optical spectra, usually around the time of peak brightness

Supernova surveys and explosion rates The SNe for which one can directly attempt to identify progenitor stars must be fairly nearby (?30 Mpc)

A decade of intensive searching fro progenitors The superbly maintained and publicly accessible archive of HST precipitated the search for the progenitors of CCSNe discovered in nearby galaxies. The Although progenitors were not discovered, the large numbers of events and the restrictive luminosity limits were to play an important role in investigating progenitor populations (see Sections 4 and 5).

overview The lower mass limit for core-collapse 8+-1 Msun 7.5–9.25 M? (9–9.25 M?) ECSNe Above 9.25 normal Fe core collapse occurs

The red supergiant problem After just the first few years of intensive systematic searching for progenitors, the lack of easy detection of moderately massive and very massive stars became an interesting issue (Smartt et al. 2003) The galaxy-integrated IMF of massive stars could be significantly steeper than α =−2. All massive stars above 17M? could produce IL- L, IIn, and IbcSNe.T

The progenitors of type II-P supernovae