Type I and
Type II Supernovas (SNs) are among the single most energetic
stellar events in the Universe.
Type I Supernovas (SNs) are the results of the explosions in white dwarf binary
star systems and Type II SNs are the deaths of massive stars. Both
types of SN involve the release of
more energy the Sun produces in its entire lifetime! (A Type II SN, in fact,
has a luminosity 100 billion times that of the current Sun and lasts for
several months--it produces more than 100 times the energy
produced by the Sun over its lifetime.)
Here, we spend most of our time looking at Type II SN, although we discuss
Type I SN as well because of their importance for Cosmology, the study of the
origin and evolution of the Universe (see Astronomy 123).
Interesting tidbits about Type II SNs:
- 99 % of the energy of a 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 I 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 was, at one time,
speculated that a SN triggered the formation of the Solar System).
- SNs are a major source of energy input into the ISM in
general
- ....
Supernova Basics
