The end of the life of a star
What happens when the nuclear fuel runs out?
- The star collapses because of the pull of gravity
Its fate depends upon its mass
- Very small stars (less than our sun) become brown dwarfs like giant Jupiters
- Small stars (like our sun) become white dwarfs collapsing to a size similar to that of the earth
- Large stars collapse to Neutron Stars or Black Holes
- Collapse causes a Supernova! Release of more energy than a galaxy from one star for a short time (months)
- For mass > 1.3 mass of our sun, becomes a Neutron Star -- Observed as Pulsars
- For mass > 1.5 mass of our sun, becomes a Black Hole Pull of Gravity so strong that nothing can escape!