A Comprehensive Study of the Magnetic White Dwarfs in DESI DR1
Abstract
As the end point of stellar evolution for most stars, white dwarfs offer powerful insight into stellar magnetism. Multiple formation channels are required to explain the observed properties of magnetic white dwarfs, and the mechanisms that produce unusual objects have potential to unlock new realms of physics. The large samples made possible by spectroscopic surveys enable study of these processes on an unprecedented level. Here we perform a detailed model atmosphere analysis of the magnetic white dwarfs in DESI Data Release 1. We identify 833 magnetic systems, 762 of which we fit using an offset dipole model. Of these, 127 targets require more in-depth analysis as they possess shallower or sharper absorption features than predicted by the offset dipole model. For these we use a patchy offset dipole atmosphere model in which the magnetic field only contributes to the line opacities at certain regions of the visible stellar disk. We compare the observed distribution of magnetic white dwarfs to the mechanisms that generate magnetic fields. We find that a core-convective dynamo that forms on the main-sequence matches the parameters of many of the magnetic systems, while a dynamo that fills the radiative interior on the giant branch reproduces many of the lower mass objects that the core-convective dynamo cannot. This sample is the largest single data release of magnetic white dwarfs to date. The diversity of formation channels and the frequency of objects with unusual field geometries highlight the power of multiplexed surveys to advance our knowledge of stellar magnetism.
Related
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- Planetary Accretion Is Less Frequent in Wide Binaries: Evidence from Metal-enriched White Dwarfs in DESI DR1
- A Spectroscopic Census of Cluster White Dwarfs from DESI, LAMOST, and SDSS
- First planetesimals from DESI DR1: 12 highly metal-rich white dwarfs
- Transport of Magnetic Fields by Thermohaline Convection in Crystallizing White Dwarfs
BibTeX
@misc{moss2026comprehensive,
title = {{A Comprehensive Study of the Magnetic White Dwarfs in DESI DR1}},
author = {Adam Moss and Pierre Bergeron and Mukremin Kilic and Warren R. Brown and Jamie Tayar},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.31565},
eprint = {2609.31565},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.31565},
}
RIS
TY - UNPB
TI - A Comprehensive Study of the Magnetic White Dwarfs in DESI DR1
AU - Adam Moss
AU - Pierre Bergeron
AU - Mukremin Kilic
AU - Warren R. Brown
AU - Jamie Tayar
PY - 2026
DA - 2026/09/25
PB - arXiv
DO - 10.48550/arxiv.2609.31565
UR - https://arxiv.org/abs/2609.31565
AB - As the end point of stellar evolution for most stars, white dwarfs offer powerful insight into stellar magnetism. Multiple formation channels are required to explain the observed properties of magnetic white dwarfs, and the mechanisms that produce unusual objects have potential to unlock new realms of physics. The large samples made possible by spectroscopic surveys enable study of these processes on an unprecedented level. Here we perform a detailed model atmosphere analysis of the magnetic white dwarfs in DESI Data Release 1. We identify 833 magnetic systems, 762 of which we fit using an offset dipole model. Of these, 127 targets require more in-depth analysis as they possess shallower or sharper absorption features than predicted by the offset dipole model. For these we use a patchy offset dipole atmosphere model in which the magnetic field only contributes to the line opacities at certain regions of the visible stellar disk. We compare the observed distribution of magnetic white dwarfs to the mechanisms that generate magnetic fields. We find that a core-convective dynamo that forms on the main-sequence matches the parameters of many of the magnetic systems, while a dynamo that fills the radiative interior on the giant branch reproduces many of the lower mass objects that the core-convective dynamo cannot. This sample is the largest single data release of magnetic white dwarfs to date. The diversity of formation channels and the frequency of objects with unusual field geometries highlight the power of multiplexed surveys to advance our knowledge of stellar magnetism.
ER -