Why do Type II Supernovae Occur?
The structure of all stars is determined by the battle between gravity and the radiation pressure arising from internal energy generation. In the early stages of a star’s evolution, the energy generation in its centre comes from the conversion of hydrogen into helium. For stars with masses of about 10 times that of the Sun this continues for about ten million years. After this time, all the hydrogen in the centre of such a star is exhausted, and hydrogen ‘burning’ can only continue in a shell around the helium core. The core contracts under gravity until its temperature is high enough for helium ‘burning’, into carbon and oxygen, to occur. The helium ‘burning’ phase lasts about a million years, but eventually the helium at the star’s centre is exhausted and it continues, like the hydrogen, ‘burning’ in a shell. The core again contracts until it is hot enough for the conversion of carbon into neon, sodium and magnesium. This lasts for about 10 thousand years. This pattern of core exhaus
Related Questions
- What type of approval does a lender need to originate and/or underwrite and/or service Title II Single Family Loans, including HECMs (Reverse Mortgages) or 203k (Rehabilitation mortgages)?
- What are the observational differences between Type 1 and Type II supernovae?
- How do the light curves differ between type I and type II supernovae?
