---
res:
  bibo_abstract:
  - The small DAHe and DAe spectral classes comprise isolated, hydrogen-dominated
    atmosphere white dwarfs that exhibit variable photometric flux and Balmer line
    emission. These mysterious systems offer unique insight into the complex interplay
    between magnetic fields, stellar rotation and atmospheric activity in single white
    dwarfs. DAHe stars have detectable magnetic fields through Zeeman-split spectral
    lines, whereas DAe stars lack such splitting. We report the first discovery and
    characterization of magnetism in the DAe white dwarf WD J165335.21−100116.33 with
    new time-resolved spectropolarimetry from FORS2. We detect a weak but variable
    longitudinal magnetic field with values Bz > −9.2 ± 2.4 kG and Bz < −2.2 ± 1.0
    kG. Independent ZTF and ATLAS photometry reveal a consistent period of P = 80.3070
    ± 0.0007 h. Time-resolved optical spectroscopy obtained with six ground-based
    instruments demonstrates strong modulation in the strength of the Hα and Hβ Balmer
    line emission with P = 80.2922 ± 0.0108 h. The photometric flux and Balmer emission
    strength vary in antiphase, with the strongest magnetic detections coinciding
    with phases of low photometric flux and strong line emission. These characteristicssupport
    the theory that a magnetically active, temperature-inverted spot/region is producing
    an optically thin chromospheric emission region. Comparison with other DAe and
    DAHe white dwarfsreveals all systems have a strikingly similar antiphase phenomenology,
    reinforcing the theory that they are subject to a unified physical mechanism.
    With the detection of a weak magnetic field, we reclassify WD J165335.21−100116.33
    as a low-field DAHe white dwarf. @eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Abbigail K.
      foaf_name: Elms, Abbigail K.
      foaf_surname: Elms
  - foaf_Person:
      foaf_givenName: Stefano
      foaf_name: Bagnulo, Stefano
      foaf_surname: Bagnulo
  - foaf_Person:
      foaf_givenName: Pier Emmanuel
      foaf_name: Tremblay, Pier Emmanuel
      foaf_surname: Tremblay
  - foaf_Person:
      foaf_givenName: Tim
      foaf_name: Cunningham, Tim
      foaf_surname: Cunningham
  - foaf_Person:
      foaf_givenName: James
      foaf_name: Munday, James
      foaf_surname: Munday
  - foaf_Person:
      foaf_givenName: John
      foaf_name: Landstreet, John
      foaf_surname: Landstreet
  - foaf_Person:
      foaf_givenName: Kareem
      foaf_name: El-Badry, Kareem
      foaf_surname: El-Badry
  - foaf_Person:
      foaf_givenName: Ilaria
      foaf_name: Caiazzo, Ilaria
      foaf_surname: Caiazzo
      foaf_workInfoHomepage: http://www.librecat.org/personId=8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
    orcid: 0000-0002-4770-5388
  - foaf_Person:
      foaf_givenName: Carl
      foaf_name: Melis, Carl
      foaf_surname: Melis
  - foaf_Person:
      foaf_givenName: Viktoria
      foaf_name: Pinter, Viktoria
      foaf_surname: Pinter
  - foaf_Person:
      foaf_givenName: Alycia
      foaf_name: Weinberger, Alycia
      foaf_surname: Weinberger
  bibo_doi: 10.1093/mnras/stag505
  bibo_issue: '1'
  bibo_volume: 548
  dct_date: 2026^xs_gYear
  dct_isPartOf:
  - http://id.crossref.org/issn/0035-8711
  - http://id.crossref.org/issn/1365-2966
  dct_language: eng
  dct_publisher: Oxford University Press@
  dct_title: Detection of a weak magnetic field in the Balmer emission line white
    dwarf WDJ1653−1001@
...