{
  "abstract": "Cataclysmic variables (CVs) are binary systems in which a white dwarf (WD) primary accretes material from a late-type secondary, typically via a disc. To date, only six CVs, all of which are non-magnetic, have been found to exhibit lags (delayed variability in one band with respect to another). In all six cases, these lags are ‘red’ (i.e. red lags blue) with a time lag of order seconds. While there is no generally accepted mechanism for producing red lags in CVs, current theories suggest reprocessing in the disc, either on the thermal or recombination time-scales, or inside-out shocks propagating through the disc. Using g-, r-, and i-band data from the OPTICAM (OPtical TIming CAMera), we report the discovery of frequency-dependent red lags from V709 Cas: a magnetic CV of the intermediate polar (IP) subclass. These red lags reach a maximum of $\\sim$4–6 s on time-scales of 7.4–13.0 min, similar to previously reported lags in non-magnetic CVs. The detection of lags in an IP is significant as the WD’s magnetic field truncates the accretion disc, limiting disc-based lag mechanisms to large radii; as a result, characteristic accretion disc time-scales cannot explain the observed lags. However, recombination can occur on second time-scales, even in systems with truncated discs. For example, we show that recombination in the disc’s bright spot, where overflowing material from the secondary meets the outer edge of the disc, plausibly explains V709 Cas’s optical spectrum, the prominence of optical spin-orbit beat pulsations, and the red lags found in this work.",
  "abstract_shown": true,
  "affiliations": [
    "School of Physics and Astronomy, University of Southampton , University Road, Southampton SO17 1BJ ,",
    "Department of Physics, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL ,",
    "Institute of Space Sciences (ICE, CSIC) , Campus UAB, Carrer de Can Magrans s/n, E-08193 Barcelona ,",
    "Institut d’Estudis Espacials de Catalunya (IEEC) , E-08860 Castelldefels (Barcelona) ,",
    "Kapteyn Astronomical Institute, University of Groningen , PO Box 800, NL-9700 AV Groningen ,",
    "Instituto Argentino de Radioastronoía (CCT La Plata, CONICET; CICPBA; UNLP) , C.C.5, (1894) Villa Elisa, Buenos Aires ,",
    "INAF – Osservatorio Astronomico di Capodimonte , Salita Moiariello 16, I-80131 Napoli ,",
    "Centre for Extragalactic Astronomy, Department of Physics, Durham University , South Road, Durham DH1 3LE ,",
    "Fluid and Complex Systems Centre, Coventry University , Coventry CV1 5FB ,",
    "Instituto de Astronomía, Universidad Nacional Autónoma de México , AP 106, Ensenada 22800, BC ,"
  ],
  "article_type": null,
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  "author_total": 12,
  "authors": [
    {
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        0
      ],
      "name": "Zackery A Irving",
      "orcid": "0009-0006-0951-3429"
    },
    {
      "affs": [
        1
      ],
      "name": "Noel Castro Segura",
      "orcid": "0000-0002-5870-0443"
    },
    {
      "affs": [
        0
      ],
      "name": "Diego Altamirano"
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    {
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        2,
        3
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      "name": "Martina Veresvarska",
      "orcid": "0000-0002-0146-3096"
    },
    {
      "affs": [
        4
      ],
      "name": "Mariano Méndez",
      "orcid": "0000-0003-2187-2708"
    },
    {
      "affs": [
        5
      ],
      "name": "Federico García",
      "orcid": "0000-0001-9072-4069"
    },
    {
      "affs": [
        6
      ],
      "name": "Domitilla de Martino"
    },
    {
      "affs": [
        6,
        7
      ],
      "name": "Simone Scaringi",
      "orcid": "0000-0001-5387-7189"
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    {
      "affs": [
        8
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      "name": "Federico Vincentelli"
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    {
      "affs": [
        9
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      "name": "Angel Castro"
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    {
      "affs": [
        9
      ],
      "name": "Federico Soto",
      "orcid": "0000-0002-3260-7240"
    },
    {
      "affs": [
        9
      ],
      "name": "Raul Michel"
    }
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  "bibtex": "https://research.draconitic.com/paper/4tvfgjy3fnmkj.bib",
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  "doi": "10.1093/mnras/stag1875",
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    "0035-8711",
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  "licence_label": "CC BY 4.0",
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  "pmcid": null,
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  "published": "2026-10-06",
  "publisher": "Oxford University Press (OUP)",
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      "origin": "journal-openalex:3103|Stellar, planetary, and galactic studies",
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  "title": "On the frequency-dependent time lags of the intermediate polar V709 Cas",
  "title_text": "On the frequency-dependent time lags of the intermediate polar V709 Cas",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:17Z",
  "url": "https://research.draconitic.com/paper/4tvfgjy3fnmkj",
  "venue": "Monthly Notices of the Royal Astronomical Society",
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      "doi": "10.48550/arxiv.2609.37185",
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      "title": "On the frequency-dependent time lags of the intermediate polar V709 Cas",
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}