Abstract

We have now discovered over 4000 exoplanets, but how can we determine their interior composition? Observations of polluted white dwarfs are unique laboratories for answers. White dwarfs are the leftover cores of low to medium mass stars which have ended their life on the main sequence. As white dwarfs are so dense, heavy elements should not be observable in their atmospheres as they sink towards the core. However, ~30% of white dwarfs are observed with heavy elements in their atmosphere, these features have been identified as planetary material. Planetary material which approaches the white dwarf is torn apart, and subsequently falls onto the atmosphere of the white dwarf. From observations of white dwarfs’ atmospheres we can discover the composition of the planetary material. This talk will bring together different observations of polluted white dwarfs to try to build up a picture of these enigmatic systems.

The talk will be followed by refreshments outside the lecture theatre.

The talk will be at the usual location of Wolfson lecture theatre in the Department of Chemistry. The entrance is the opposite side of the building to Bristol-Myers-Squibb Lecture theatre and is opposite the car park- shown by the red arrow on the map. https://map.cam.ac.uk/Department+of+Chemistry#52.197964,0.125242,18

Tickets are £2 or free for members. Annual membership (£7) and life membership (£12) can also be purchased at the event – please bring cash. The talk will be followed by refreshments outside the lecture theatre.