EXTREME STARS

From the biggest and brightest to the smallest and dimmest, we take a look at some stellar extremes

- Andrew May

The Sun produces heat and light through nuclear fusion, converting hydrogen into helium. In this respect, it’s a pretty typical star. Around 90 per cent of all stars are undergoing the same process, referred to as the main sequence of the stellar life cycle. Even so, there are some striking exceptions, such as stars of very low or very high mass or ones that have exhausted all their nuclear fuel. Here we take a look at some of these extreme stars – from brown dwarfs to supergiants and from neutron stars to weird hybrid stars. But first it’s worth reviewing the basics of stellar evolution.