Dr Sarah Casewell

STFC Ernest Rutherford Research Fellow and Lecturer

Department: Physics & Astronomy, School of

Telephone: 0116(0) 252 3549



I am an observational astronomer researching irradiated brown dwarfs brown dwarfs white dwarfs exoplanets and M dwarf binaries. In 2019 I began an STFC funded Ernest Rutherford Research Fellowship researching irradiated brown dwarfs and their similarities to hot Jupiter exoplanets.

Outside of research I am co-chair of the Women's staff forum representing all who identify as women at the University.


I research irradiated brown dwarfs brown dwarfs white dwarfs exoplanets and M dwarf binaries.

My Fellowship research focuses on brown dwarfs irradiated by a white dwarf companion. In these fascinating systems the brown dwarf survived as its companion star evolved first into a giant and then a white dwarf. The brown dwarf is left very close to the white dwarf in an orbit of a few hours meaning they are highly irradiated by their companions resulting in large temperature and atmospheric differences between the day- and nightsides. There are very few of these objects known to date and I have been involved in the discovery 5 of them including the most irradiated brown dwarf known in a 68 min orbit around a 25000 K white dwarf and the only inflated brown dwarf known to orbit a white dwarf.

I am part of the NGTS consortium leading the M dwarf working group and an official collaborator to the Zooniverse Backyard Worlds science team. I lead the ESA Ariel mission working group on brown dwarfs.

I am the Vera Rubin Observatory LSST UK Person of contact for variable stars and an ESA community scientist for the Ariel mission.



(0) My publication list may be found here:

My top 10 selected publications are below:
Kirkpatrick et al., (2021):  The Enigmatic Brown Dwarf WISEA J153429.75-104303.3 (a.k.a. "The Accident"), ApJL, 915, 6
Casewell, S.L., et al., (2020): WD1032+011, an inflated brown dwarf in an old eclipsing binary with a white dwarf, MNRAS, 497, 357
Meisner et al., (2020), Spitzer follow-up of extremely cold brown dwarfs discovered by the Backyard Worlds: planet 9 citizen science project, ApJ, 899, 123 
Casewell, S.L., et al., (2018), The direct detection of the irradiated brown dwarf in the white dwarf-brown dwarf binary SDSS J141126.20+200911.1, MNRAS, 481, 5216.
Casewell, S.L et al., (2018), The first sub-70 min non-interacting WD-BD system: EPIC212235321, MNRAS, 476, 1405
Longstaff, E.L., Casewell, S.L., et al., (2017), Emission lines in the atmosphere of an irradiated brown dwarf. MNRAS, 471, 1728
Bayliss, D. et al., (2017), NGTS-1b: a hot Jupiter transiting an M-dwarf. MNRAS, 475, 4467
Casewell., S.L et al., (2015): Multiwaveband photometry of the irradiated brown dwarf WD0137-349B. MNRAS, 447, 3218
Helling, Ch, & Casewell, S.L., (2014): Atmospheres of brown dwarfs, A&Arv, 22, 80
Casewell, S.L., et al., (2009), High-resolution optical spectroscopy of Praesepe white dwarfs. MNRAS, 395, 1795



I supervise PhD students in observational astronomy on the topics of brown dwarfs and white dwarfs as well as exoplanets and binary M dwarfs with the NGTS project.


I supervise advanced research projects and literature review projects in the School of Physics and Astronomy.

Press and media

 I am happy to be contacted about the Next Generation Transit Survey (NGTS) the Zooniverse Backyard worlds citizen science project brown dwarfs white dwarfs and exoplanets. I am co-chair of the Women's Forum at the University and am happy to talk about women in STEM and academia.


I am a fellow of the Royal Astronomical Society


NASA Robert H. Goddard group award to Backyard Worlds (2021).

The Women’s Awards East Midlands Outstanding Woman in STEM Runner up (2020).

Royal Astronomical Society Group Award for the UKIDSS consortium (2012).

Prime Minister’s Inspiring Young Scientists Reception Downing Street (2007). 

Media coverage

I have been interviewed on BBC Radio Leicester and quoted in New Scientist Scientific American and Quanta magazines. I have also been interviewed for the Exocast and the UK Space Conference podcasts.
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