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The Question
(Submitted November 23, 2003)
I know that there are different types of supernova explosions:
What do these mean? Do they account for how big the explosion is?
The Answer
Thank you for your question. As is the case with most astronomical
objects and phenomena, supernovae are classified according to their
basic observable characteristics -- in this case particular features
of their optical spectra and behavior of their "light curves" (how
their brightness changes with time).
For example, the Type I (Ia, Ib and Ic) are distinguished from Type
II by the absence of hydrogen spectral emission lines in the former
(and their presence in the latter). In addition, type Ia are always
the same mass and thus the same luminosity, which is why they are
considered to be standard candles.
For more details, please see one or more of the following sites:
http://imagine.gsfc.nasa.gov/docs/science/know_l2/supernovae.html,
http://en.wikipedia.org/wiki/Supernova,
http://rsd-www.nrl.navy.mil/7212/montes/snetax.html,
and
http://www.jca.umbc.edu/~george/html/courses/2002_phys316/lect12/lect12_sn_basics.html,
where you can also find information on the different physical
characteristics of these different types.
Most supernovae of all classification are believed to have roughly the
same amount of energy released.
-- Michael Loewenstein and Amy Fredericks for "Ask an Astrophysicist"
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