Lecture 13 - Life history of stars – Massive stars
This lecture endeavours to take the students through the many acts of the `stellar drama' that unfolds in the most massive stars of the Universe. Interestingly, a crucial piece of physics comes from a somewhat obscure but classic 1932 paper by S. Chandrasekhar, which helps us to understand the final stages of this drama that end in the spectacular fireworks of a Supernova.
In massive stars (mass greater than roughly 10 solar mass) fusion reactions proceed all the way till Iron – the most stable nucleus – is formed. That signals the end of the ‘stellar drama’. When the mass of the iron core increases to a critical value, it collapses, triggering the explosion of the envelop of the star. These concepts are explained from the first principles in this lecture.