DESI DR1 Delivers Largest Spectroscopic White Dwarf Catalogue with 44,409 Confirmed Objects

DESI targeted stars alongside its primary extragalactic redshift survey, yielding spectra for 63,968 candidate objects that were visually inspected and model-fitted to classify 44,409 white dwarfs. The team derived atmospheric parameters, radial velocities, and spectral types while assigning confidence scores and flagging fibre contamination risks from nearby sources. Completeness and uniformity assessments enable statistically robust population studies that were previously limited by smaller, heterogeneous samples.

This catalogue connects directly to white dwarf cooling sequences used in cosmochronology and to constraints on binary evolution channels that also shape Type Ia supernova progenitors. Unlike targeted searches, DESI's magnitude-limited, fibre-fed approach reveals underrepresented classes such as magnetic and metal-polluted white dwarfs across a wide range of Galactic populations.

Prior catalogues from SDSS and Gaia lacked the uniform spectroscopic coverage and radial velocity precision now available; the new data should tighten space-density measurements and improve tests of white dwarf crystallization physics. Future DESI releases will extend the sample size and temporal baseline, allowing kinematic tagging of thin-disk, thick-disk, and halo white dwarfs.

The main limitation is reliance on single-epoch spectra and visual classification, which may miss rare or composite systems; multi-epoch observations and automated classification pipelines would strengthen statistical power.