White Dwarfs

Guest Speaker

Thursday, 23rd July 2020 (19:45 - 21:00)

Venue: Virtual Meeting

I’ll be talking about white dwarfs, their formation and evolution and how astronomers use them as clocks, particularly in binaries. I’ll then talk a little bit about my research on white dwarfs with very low mass companions - brown dwarfs.

White dwarfs are the end state of stellar evolution for most stars. These Earth sized degenerate objects are extremely hot, cool over time, and the majority have pure hydrogen atmospheres. By monitoring their cooling, we are able to use them as a clock to determine the age of companion stars. Metal pollution in their atmosphere reveals information about the interstellar medium, and also the remnants of destroyed rocky planets. I will talk about the fundamental properties of white dwarfs and what they reveal about their environments and companions. 

Speaker: Dr. Sara Casewell

White and brown dwarfs are my areas of interest as an observational astronomer. I have written articles on a variety of subjects, including new L dwarfs in Blanco 1, the Hyades, and Praesepe, the white dwarf starting mass-final mass ratio, and the first T dwarfs in the Pleiades.

I'm now looking at brown dwarfs that are in close binary systems with white dwarfs and how irradiation affects the brown dwarf's atmosphere. In January 2019, I started my STFC Ernest Rutherford Fellowship researching radioactive brown dwarfs.

I am the LSST contact for the Solar Neighbourhood in the UK and I am the coordinator of the Ariel brown dwarf working group.