What are the observational differences between Type 1 and Type 2 supernovae?
The basic difference between the type Ia and type 1b, 1c, and II supernovas is that the Ia supernovas are compact objects (white dwarfs) at the beginning and have to expand a great deal before reaching their peak brightness. In addition, most of the light from Ia supernovas comes from the decay of radioactive nickle-56 and cobalt-56, which are produced in much greater amounts (5-6X) than are produced in other supernovas (core collapse types). Core Collapse supernovas reach peak brightness faster and then slowly fade out. Type Ia supernovas gain slowly in brightness, as they expand, then maintain their peak brightness for a longer period of time.
