{
  "abstract": "The fastest spinning white dwarfs (WDs), which approach break-up speeds, are found in close binary systems. In the two known magnetic WD ``propellers'', AE~Aqr and LAMOST J0240+1952, the magnetic WD spins so rapidly that it ejects the material transferred by its Roche-lobe-filling companion rather than accreting it. We report the discovery of the third such system, 1eRASS J042633.5$-$250226 (1eRASS J0426/Valeria), at only 265 pc, identified by combining SRG/eROSITA and \\textit{Gaia} data via the ``X-ray Main Sequence''. TESS photometry shows AE~Aqr-like flaring and orbital modulation with $P_{\\mathrm{orb}} \\approx 6.62$ hr, and ZTF shows month-long high/low state changes. Phase-resolved Palomar/DBSP spectroscopy confirms the orbital period and yields a donor radial velocity of $K_2 = 202\\pm7$ km s$^{-1}$. High-speed Palomar/CHIMERA photometry detects optical pulsations on three nights with the strongest detection at $P_\\textrm{spin} = 26.8$ sec, though further observations are needed to confirm this as the WD spin. Spectral fitting of the donor in the low state reveals a late K-type star with $T_{\\mathrm{donor}} = 4100\\pm150$ K. Zeeman splitting in the optical spectrum yields a candidate field strength of $B_{\\mathrm{WD}} = 26 \\pm 3$ MG, meaning the system will evolve into a polar. Like other WD propellers, the system is X-ray faint ($L_X \\approx 7\\times 10^{30}$ erg s$^{-1}$), but is not detected in the radio, and a spin period is not detected in X-rays by SRG/eROSITA. The proximity of this system and evolutionary model constraints on the timeframe of the propeller phase yield a birth rate density of $\\sim8\\times10^{-16} \\textrm{pc}^{-3} \\textrm{yr}^{-1}$, which agrees with that of magnetic CVs, suggesting that a substantial fraction of magnetic CVs pass through a propeller phase.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.10689",
  "author_total": 14,
  "authors": [
    {
      "name": "Antonio C. Rodriguez"
    },
    {
      "name": "Kareem El-Badry"
    },
    {
      "name": "R. Michael Rich"
    },
    {
      "name": "Kevin N. Ortiz Ceballos"
    },
    {
      "name": "Ingrid Pelisoli"
    },
    {
      "name": "Casey J. Law"
    },
    {
      "name": "Kaya Mori"
    },
    {
      "name": "Boris Gaensicke"
    },
    {
      "name": "Edo Berger"
    },
    {
      "name": "Liam Connor"
    },
    {
      "name": "Ilkham Galiullin"
    },
    {
      "name": "Ilaria Caiazzo"
    },
    {
      "name": "Matthew Graham"
    },
    {
      "name": "Samuel Whitebook"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/28akadahx998v.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.10689",
  "fulltext_url": null,
  "id": "28akadahx998v",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.10689",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.HE"
    ],
    [
      "openalex",
      "3103|Astrophysical Phenomena and Observations"
    ]
  ],
  "openalex": "W7221082476",
  "pdf_url": "https://arxiv.org/pdf/2610.10689",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-07",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/28akadahx998v.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:54Z",
      "native_id": "2610.10689",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.10689"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "Discovery of a Nearby Ultra-fast Magnetic White Dwarf Propeller: Common Pathways to Magnetic Cataclysmic Variables",
  "title_text": "Discovery of a Nearby Ultra-fast Magnetic White Dwarf Propeller: Common Pathways to Magnetic Cataclysmic Variables",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:54Z",
  "url": "https://research.draconitic.com/paper/28akadahx998v",
  "venue": "arXiv",
  "versions": []
}