Description
Organisers: Andy Buchan, Emily Roberts, Jamie Williams
Although the field of white dwarf research in the UK is rapidly expanding, meetings focused on this subject remain infrequent. Following the success of the white dwarf session at NAM 2022, we propose another session in 2025 to allow the presentation of new work, particularly by early career researchers. There have been many new developments in the field since the last NAM session. These include data releases from JWST and DESI, as well as the application of machine learning techniques to white dwarf spectra. With the primary white dwarf meeting, EuroWD, only occurring biennially and the next conference being held in Boston, there are few opportunities for early career researchers in the UK to present their work and for collaborations to begin and be fostered. As the previous white dwarf session envisioned, we propose white dwarf NAM meetings in the off-years from EuroWD, in order to grant more chances for the community to meet. We invite talks on any topic related to white dwarfs including, but not limited to, stellar archaeology, evolved planetary systems, white dwarf modelling, and supernovae. These topics will not only help progress our understanding of white dwarfs, but will have wide-ranging impacts on other areas of astronomy, including planet formation, galactic evolution and transients. We will give priority to early career researchers, allowing them an opportunity to present their work and develop collaborations with the wider community.
The recent discoveries of transits around white dwarfs have provided unique and powerful insights into their circumstellar debris discs. This family of white dwarfs with transiting debris exhibits significant diversity, where some display line-of-sight gas absorption while others are highly dynamic with large scale heights.
In 2022, a white dwarf was reported to have transiting debris at an...
White dwarfs with a F, G or K type companion represent the last common ancestor for a plethora of exotic systems throughout the galaxy, though to this point few of them have been fully characterised in terms of orbital period and component masses, despite the fact several thousand have been identified. Gaia DR3 has examined many hundreds of thousands of binary systems, and as such we can use...
At least a quarter of white dwarfs display signatures of atmospheric pollution of heavy metals in their spectra, caused by the accretion of planetary debris. This debris is thought to originate from planetesimals that are tidally disrupted, forming a debris disc. The material in the disc is then accreted onto the white dwarf, generating the pollution we observe. I will discuss how this...
The first data release from the Dark Energy Spectroscopic Instrument has yielded the largest sample of spectroscopically-confirmed white dwarfs, observed in an almost-unbiased, magnitude-limited survey. Our catalogue contains over 40000 white dwarfs, around two-thirds of which are newly-identified, all with spectral classifications and stellar parameters from model-fitting. Highlights include...
We observe in nature overly luminous Type Ia supernovae which, if we take to have originated from the deflagration of a CO white dwarf, would imply a progenitor with a mass in excess of the Chandrasekhar mass. There are a number of possible mechanisms by which such a super-Chandrasekhar mass white dwarf may be supported. We consider the presence of a large (>10โถ G) magnetic field in the white...
The vast majority of stars -- $\sim$95\% -- are born with masses below 8-10 M$_{\odot}$ and will eventually evolve into a white dwarf. Because of this, white dwarfs play an integral role in deepening our understanding of the structure and evolutionary history of stellar bodies. They, however, present observational limitations because of their Earth-like radius and low luminosity. Since about a...
ELMs are white dwarf stars with masses that are too low ($\lesssim$ 0.3 $M_\odot$) to be formed through single stellar evolution. Many of the observed ELMs have been found to be strong gravitational wave sources that will be detectable by LISA. Their higher brightness compared to canonical white dwarfs makes them valuable laboratories for the development of multi-messenger astronomy. Binary...
We present high resolution archive spectra of four white dwarfs taken over a period of 25 years. The observations were taken with ESOs Ultraviolet and Visual Echelle Spectrograph (UVES) and there are between 400 and 625 spectra per wavelength setting per star. The primary aims of the study are to search for changes in interstellar lines and those in the Earth's atmosphere as a function of...
Second generation planets are formed in the post-asymptotic giant branch (AGB) phase. The synthesis of elements during the AGB phase will mean that second generation planets would have different compositions to first generation planets. Specifically, they would have enhancements in the trans-iron s-process elements.
I will present a hot (T$_\mathrm{eff}=35\,500\,$K) white dwarf which is...
Gaia continues to provide excellent observations of white dwarfs with unparalled precision, accuracy, and sample size. This allows us to revisit methods of inferring the star formation history (SFH) of the solar neighbourhood using white dwarfs. The absolute Gaia G magnitude distribution of white dwarfs and the white dwarf luminosity function are expected to have a dependence on the...
In the era of new large-scale surveys, the number of confirmed white dwarfs (WDs) has reached several hundred thousand. With such vast datasets, it has become increasingly feasible to derive more specialized samples for separate analyses from the general WD population. Krzesiลski et al. (2009) focused on analysing and determining the luminosity function of only hot WDs (Teff >20,000 K),...
White dwarfs which are โpollutedโ with metals can be used to gain unique insights into the geology of exoplanetary material. These objects provide evidence that iron core formation and incomplete condensation, the key geological processes defining Earthโs first order structure and composition, also operate in exoplanetary systems. However, analysis of polluted white dwarfs is complicated by...
