Constraining the composition of exo-planetary material around white dwarf stars

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• Amy Steele (MSI Postdoctoral Fellow, McGill Space Institute)
• Tuesday 09 November 2021, 13:00-14:00
• Ryle seminar room + ONLINE - Details to be sent by email.

If you have a question about this talk, please contact Paul B. Rimmer.

There is evidence that main sequence (MS), giant, and white dwarf (WD) stars have circumstellar (C-S) material that originates from the small-body populations of their planetary systems. How (if at all) are the planetesimals around MS and WD stars related? One way to address this question is to begin at the end of the stellar life cycle for sun-like stars, with the approx 30% of WDs that have unexpected heavy elements in their photospheres. This pollution likely arises from the accretion of planetesimals that were perturbed by outer planet(s) to the WD’s tidal radius. These planetesimals sublimate, turning into C-S gas, and accrete onto the WD surface. In this talk, I describe a method to determine the abundances of elements producing C-S gas features in the spectra of the approx 30 known polluted WDs with emission features and highlight my current efforts to build a database of models for these types of systems. This work will provide a key to quickly understand the instantaneous composition of the material flowing from these (exo) planetesimals and will eventually make this type of modeling more accessible in the future.

This talk is part of the Exoplanet Seminars series.

This talk is included in these lists:

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

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