Type I and
Type II Supernovas (SNs) are among the single most energetic
stellar events in the Universe. There are three types of Type I SNs; Type Ia SN,
Type Ib SN, and Type Ic SN. There are two types of Type II SNs; Type II-P SN,
supernovas with plateaus in their light curves and Type II-L SN, supernovas
whose light curves fall off roughly exponentially.
Type Ia Supernovas (SNs) arise from explosions of white dwarfs, perhaps in binary
star systems, while Type Ib and Ic Supernovas result from the explosions of
massive stars. and Type II Supernovas result from core collapse in massive stars.
Both types of SN, Types I and II, involve the release of more energy over a fraction
of a second than does the Sun over its entire 10 billion year lifetime! (Even in
only its light show, a Type II SN produces
more light than
produced by the Sun over its lifetime.)
Here, we spend most of our time looking at Type II SN although we do spend
a fair amount of discussion on
Type Ia SN as well because of their importance to Cosmology, the study of the
origin and evolution of the Universe (Astronomy 123).
Interesting tidbits about Type II SNs:
- 99 % of the energy of a Type II SN
comes out as neutrinos
- ~1 % of the energy goes into kinetic energy, the motional energy of the ejected material
- only 0.01 %
of the energy goes into the visible fireworks (electromagnetic radiation)
seen in the sky.
Even this tiny amount of visible energy allows Type II
SN to stand out against the background light of entire galaxies
(see above)!
Type I and Type II SNs are impressive beasts and are interesting simply from
this standpoint, they, however, are interesting for other reasons too.
- SNs produce most of the heavy elements
found in the Universe
- Type Ia SN are standardizable candles and observations of Type I SN
at large redshift z yielded the first believable evidence that the
expansion of the Universe was speeding up and not slowing down today.
- Type II SN can trigger star formation (it has at times been
speculated that a SN indeed triggered the formation of the Solar System).
- SNs are a major source of energy input into the ISM in
general
- ....
Supernova Basics
