Supernovae (SNe) are stellar explosions and stars may explode for different reasons. Low mass stars explodes when a companion dumps mass on them, high mass stars explode because they are too heavy for their own sake, and the gravity at the center gets too high for nuclear reactions to compete with it and maintain the star in a "steady state".

The spectra of SNe tell us which explosion we are witnessing. Below is a graphic explanation of the classification scheme for the main types of SNe: SN Ia, Core collapse type II, and stripped envelope SNe, subdivided in Ib, Ic, and Ic-BL

Scroll over the spectrum of each SN to see which progenitor it comes from and what drive the classification.

this is a prototype of the sclassification scheme designed by maryam modjaz ca. 2008 with updated templates for the stripped SN, instead of individual spectra.
todo: smooth animations, add animations to explain each element on mouse over, improve BB continuum
also we need a description of the whole thing in the webpage