- I am a second year PhD student in the Astronomy and Astrophysics group at the University of Warwick. My research primarily focuses on double-white-dwarf binary stars. White dwarfs mark the endpoint of stellar evolution for intermediate-mass main-sequence stars, and will inevitably be the final stage of evolution for the Sun. However, the presence of a binary companion can majorly alter the evolution away from that of an isolated star. With two white-dwarf stars together as a binary, over time significant angular momentum can be lost from the system through the means of gravitational wave radiation, to the point where the stars spiral closer and closer together and hence radiate gravitational waves stronger.
I investigate systems exhibiting this effect using observational data to explore some of the final stages of stellar evolution close to the point of collision, where the orbital decay can be used to gain ultra-precise characterisation of system masses. Furthermore, for the most compact of systems, I strive to investigate the impact of mass transfer, tidal effects, and the potential presence of third bodies. By doing this, my research has an immediate implication to understand type 1a supernovae, where the merger of a double white dwarf binary is a leading candidate to explain such an event.
A second part of my research is to exploit state-of-the-art wide-field surveys such as Gaia to identify promising double white dwarf binary candidates. After finding systems, I will lead photometric and spectroscopic observations to firstly confirm the type of system and to then investigate those that are most interesting. Also, I will perform large population analyses of the double white dwarf systems with predictions for the number that will be detectable with the Laser Interferometer Space Antenna (LISA) mission, set to launch in 2034.
J. Munday et al. "An Eclipsing 47 minute Double White Dwarf Binary at 400 pc". In MNRAS (Aug. 2023), arXiv: 2308.00036
J. Munday et al. “Two decades of optical timing of the shortest-period binary star system HM Cancri". In: MNRAS (Feb. 2023), arXiv: 2211.09834
J. Munday et al. “The post-common-envelope binary central star of the planetary nebula ETHOS 1Link opens in a new window”. In: MNRAS (Sept. 2020), arXiv: 2009.03577Link opens in a new window
Green, M et al. "TIC 378898110: A Bright, Short-Period AM CVn Binary in TESSLink opens in a new window", in MNRAS (Jan. 2024), arXiv: 2311.01255Link opens in a new window
Bostroem, K et al. “Early Spectroscopy and Dense Circumstellar Medium Interaction in SN 2023ixfLink opens in a new window”, In APJ (Oct. 2023), arXiv: 2306.10119Link opens in a new window
Caiazzo, I et al. "A rotating white dwarf shows different compositions on its opposite faces". In Nature Astronomy (July. 2023). arXiv: 2308.07430
Levan, A et al. "JWST detection of heavy neutron capture elements in a compact object merger". arXiv: 2307.02098
Elms, A et al. "An emerging and enigmatic spectral class of isolated DAe white dwarfs". In MNRAS (July. 2023), arXiv: 2307.09186
Pelisoli, I et al. "A 5.3-min-period pulsing white dwarf in a binary detected from radio to X-rays". In: Nature Astronomy (June. 2023). arXiv: 2306.09272
Schwope, A et al. "X-ray properties of the white dwarf pulsar eRASSU J191213.9−441044". In: A&A (June. 2023). arXiv: 2306.09732
Geier, S. A et al. "The first massive compact companion in a wide orbit around a hot subdwarf star". In: A&A (May. 2023). arXiv: 2305.03475
Brown. A et al. "Photometric follow-up of 43 new eclipsing white dwarf plus main-sequence binaries from the ZTF survey". In: MNRAS (May. 2023). arXiv: 2302.11392
D. Jones et al. "A detailed study of the barium central star of the planetary nebula Abell 70". In MNRAS (November. 2022). arXiv: 2208.14778
A. Pastorello et al. “Forbidden hugs in pandemic times. I. Luminous red nova AT 2019zhd, a new merger in M 31Link opens in a new window”. In: A&A (Feb. 2021), arXiv: 2011.10588Link opens in a new window
D. Jones et al. “The post-common-envelope binary central star of the planetary nebula PN G283.7-05.1. A possible post-red-giant-branch planetary nebula central starLink opens in a new window”. In: A&A (Oct. 2020). arXiv: 2007.08960Link opens in a new window
Isaac Newton Group
Parallel to my PhD, I worked as a support astronomer working with the 2.5m Isaac Newton Telescope on the island of La Palma, Canary Islands. Here, I maintained the upkeep of the telescope and regularly taught visiting observers to operate the telescope and to optimise its potential. I was in charge of performing instrumental setup changes and I taught the 2023/24 generation of PhD students how to operate the telescope.
Prior to Warwick, I studied at the University of Surrey and a Master's research year with the Instituto de Astrofisica de Canarias (IAC) in La Palma, Canary Islands. There I researched binary central stars of planetary nebulae, which are the immediate result of a mass transfer phase which engulfs the central stars and is abruptly ejected. I characterised and analysed the systems ETHOS 1Link opens in a new window and Ou 5, with key results of very massive and hot primary stars in both cases compared to the investigated sample of binary central planetary nebulae. Also, the work of ETHOS 1 verified a binary-nebula inclination relation and a lack of inflation of the companion main sequence star, while the study of Ou 5 indicates a younger primary star (a pre-white dwarf post-nebula ejection) evolutionary path, ejecting the nebula during a post-RGB evolutionary state opposed to the dominant post-AGB pathway. The motivation for these investigations again revolved about classifying stellar evolutionary tracks for intermediate-mass stars, except at a much earlier stage of a binary's lifetime to a double white dwarf binary.
I often perform observations on telescopes around the world. I have been fortunate enough to spend dozens of nights using the WFC and IDS instruments at the Isaac Newton Telescope (INT) and on ALFOSC at the Nordic Optical Telescope (NOT), La Palma. I have observed in person and remotely with ULTRACAM, currently mounted on the 3.5m ESO New Technology Telescope (NTT), and remotely with ULTRASPEC and HiPERCAM, mounted on the Thai National Observatory (TNO) and the 10.4m GTC respectively . Additionally, I have conducted visitor-mode observations in La Palma and Chile as the principal investigator.
I taught an undergraduate astronomy experiment in 2nd year labs where students calibrate spectra of the Sun using basic telescope equipment and CCDs to derive its radial velocity and temperature. I actively taught visiting astronomers on the 2.5m INT telescope.