Polluted White Dwarfs: Insights into Ancient Exo-Planetary Systems

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• John Harrison (University of Cambridge)
• Tuesday 09 June 2020, 16:00-17:00
• ONLINE - Details to be sent by email.

If you have a question about this talk, please contact Dr Annelies Mortier.

As the study of rocky exo-planets enters an era of characterisation, the ability to determine how similar a planet is to the Earth, and thus if it is potentially habitable, is fast approaching. An understanding of the geological processes which determine a rocky world’s bulk composition, geodynamics, and subsequent climate is of vital importance to this pursuit. Over the course of my PhD I have used the pollution of white dwarf stars by rocky exo-planetary material to gain insights into the bulk composition of rocky exo-planets, and thus, the geological processes which occur on them. I have created a model which reproduces the atmospheric metal abundances present in polluted white dwarf stars and generates constraints on the origin of the polluting material. Using this model I can constrain the mass of the polluting bodies, their formation temperature, and whether they experienced geochemical differentiation and formed iron-nickel cores and magnesium silicate mantles similar to the rocky worlds of the Solar System. In this talk I will outline the model and discuss the insights it provides into the origin and geology of rocky exo-planetary material. Additionally, I will discuss how polluted white dwarf systems may be used to constrain the interior compositions of exo-planets in an analogous manner to how the Solar System meteorite suites allowed the Earth’s interior to be constrained.

This talk is part of the Exoplanet Seminars series.

This talk is included in these lists:

• Combined External Astrophysics Talks DAMTP
• Cosmology, Astrophysics and General Relativity
• Exoplanet Seminars
• Institute of Astronomy Talk Lists
• LCLU Departmental Talks
• ONLINE - Details to be sent by email

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