Question: based on what you're researching right now, what have you learnt so far about space, planets and stars?

Miriam Hogg answered on 9 Nov 2018:

I think the main thing i’ve learnt is that it’s not all about how things start!

The current ideas about how planets form is that they form at around the same time as the star, from the same material. That star then burns its fuel and eventually dies, first by expanding into a giant, then blowing its outer layers off, leaving a tiny core which we call a white dwarf. It has always been assumed that nothing really happened to the planets, they might survive the giant phase and carry on orbiting the dwarf, or they might get destroyed.

However I’ve been working on the last part of a stars life. When it throws off its outer layers, that material can actually be recycled into new planets in some situations!

So we can have old dead stars with new planets around them! We might look at a star with planets around it but when that star dies the planets around it might be completely different. This idea makes it extra important to look at old stars and white dwarfs.