HISTORY

--Dramatic event – outshine Venus, visible even in daylight. There are cave drawings of these events which are 10,000 years old.

How often? ~100 years between, per galaxy

1054 – Special

Chinese documented light curve – compared to others.

Rediscovered by Messie – M1

The Crab Nebula

An astronomers delight:

Emits radio, visible, and x-rays

Contains a pulsar at center – this is the supernova/pulsar link

Appearance

at maximum light M_v ~ -19 (10⁹ –10¹⁰ times L_sun)

type II is 2 times less

puts out 10⁴⁹ ergs

Type I – Spectra show broad features – not understood

Type II – Ejects far more mass than type I

Evolution to Supernova

Stellar Mass ranges

~1 Msun Main sequence life > universe

<~ 8 Msun White dwarfs

<~ 10 Msun Carbon Detonation – degenerative core burning

Shell Burning

>~ 100 Msun Pair formation supernova

steps 3 and 5 may not occur often

Most supernovae come from shell burning

Source of all heavy elements

"We are all from the stars"

The Orion Skin Model

(Ne core)

(O core)

(Si core)

works up tp Fe +Ni à Fe-Ni core

When this process endes, Fe-Ni core collapses. Runaway burning – explosive nucleosynthesis.

Generates trans Iron

Energy released:

10⁴⁹ ergs visible

10⁵¹ ergs kinetic

~10⁵⁴ ergs neutrinosß basic pressure source