{
  "abstract": "PSR~J1757$-$1854, a 21.5\\,ms pulsar, is a highly relativistic double neutron star (DNS) system in a tight eccentric ($e = 0.61$) 4.4\\,hr orbit. With extremely large gravitational wave luminosity and one of the fastest orbital decay rates of any known DNS system, it is ideal for testing general relativity (GR) in the strong-field regime. Here we present results from a high-precision timing campaign combining archival data from the Murriyang telescope and Green Bank Telescope (GBT) with new high-sensitivity observations from the MeerKAT radio telescope and additional observations from the GBT. The extended baseline and superior sensitivity of MeerKAT have yielded substantial improvements to previously measured post-Keplerian parameters by a factor of around $\\sim2$ or more. We report the first detection of the relativistic angular deformation, $δ_θ$ in this system, making PSR~J1757$-$1854 only the third DNS system for which $δ_θ$ has been measured, achieved here in just 9 yrs compared to the decades of timing required for both the double pulsar and the Hulse-Taylor binary. We demonstrate how $δ_θ$ can be used to constrain the spin-orbit geometry of the system, ruling out two of the four geometric solutions previously identified, while remaining consistent with GR. We also evaluate higher-order contributions to the periastron advance $\\dotω$, including the second post-Newtonian correction and the Lense-Thirring term, and show that these have a measurable systematic effect on the inferred total system mass. The observed orbital period derivative, $\\dot{P}_\\mathrm{b}$ remains consistent with the GR prediction for gravitational-wave damping across a wide range of plausible distances.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.23926",
  "author_total": 15,
  "authors": [
    {
      "name": "Jaikhomba Singha"
    },
    {
      "name": "Vivek Venkatraman Krishnan"
    },
    {
      "name": "Marisa Geyer"
    },
    {
      "name": "Victoria Blackmon"
    },
    {
      "name": "Paulo Freire"
    },
    {
      "name": "Norbert Wex"
    },
    {
      "name": "Maura McLaughlin"
    },
    {
      "name": "Michael Kramer"
    },
    {
      "name": "Amanda Weltman"
    },
    {
      "name": "David Champion"
    },
    {
      "name": "Matthew Bailes"
    },
    {
      "name": "Sarah Buchner"
    },
    {
      "name": "Fernando Camilo"
    },
    {
      "name": "Andrea Possenti"
    },
    {
      "name": "Maciej Serylak"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cgd1matx5x01r.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.23926",
  "fulltext_url": null,
  "id": "cgd1matx5x01r",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.23926",
  "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": null,
  "pdf_url": "https://arxiv.org/pdf/2606.23926",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-06",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cgd1matx5x01r.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:22Z",
      "native_id": "2606.23926",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.23926"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "Detection of relativistic orbital deformation from improved timing of PSR J1757$-$1854",
  "title_text": "Detection of relativistic orbital deformation from improved timing of PSR J1757−1854",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:22Z",
  "url": "https://research.draconitic.com/paper/cgd1matx5x01r",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1093/mnras/stag1861",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}