Richard Hall gave a most interesting overview of the types of stars.
Starting with the structure of our own sun we were next taken on a tour of Antares in Scorpius and Betelgeuse in Orion. Placing these stars in the same position as our sun creates a real impression of size and temperature. The talk then moved onto rapidly spinning blue stars and down to small red dwarfs such as Proxima Centauri.
Putting order to these stars leads to the Hertzsprung-Russell diagram. We toured through the main sequence, learned about Bolometric magnitude and spectral classes. Stellar physics was introduced with the energy balance and the pressure balance within stars.
We looked at different scenarios like doubling the mass of the sun and finding that would be very unfortunate for its lifespan, down to 1.3 billion years.
Some stars come with very small masses, such as those of approximately 8% of the mass of our sun which turn into brown dwarfs, through to the other extreme. These massive stars of 40 solar masses can't maintain the energy or pressure balances. Then even larger are those of 200 solar masses that disrupt at birth.
The talk finished up following the life of the sun as it moved to an M or K type star, expansion and final cooling.
Our evening finished with tea and coffee. Thanks to Richard for a really interesting and educational talk.