{
  "abstract": "Stellar orbits probe the metric of and mass around the Sgr A* massive black hole. To enable study of the black hole, the surrounding mass, and tests of gravity, a precise reference frame must be established and maintained. We present an updated stellar maser-based reference frame for the inner parsec of the Galactic Center, referenced to the radio continuum of Sgr A*. This work synthesizes 30 years of astrometric observations of 15 SiO stellar masers and the Sgr A* continuum at 43 GHz. The uncertainty in the mean offset of the maser ensemble from Sgr A* is 0.08 mas in the current epoch and will decay to 0.10 mas by 2030. At a distance of 8.2 kpc, these correspond to position uncertainties of 0.6 AU and 0.8 AU, respectively, which is similar to or smaller than the stellar SiO-emitting region. The mean maser proper motion uncertainties are 0.05 mas yr$^{-1}$ in RA and 0.08 mas yr$^{-1}$ in Dec, corresponding to 1.8 km s$^{-1}$ and 3.2 km s$^{-1}$. The reference frame stability between IR and maser astrometry is 10~$μ$as yr$^{-1}$ (0.40 km s$^{-1}$) in RA and 15 $μ$as yr$^{-1}$ (0.57 km s$^{-1}$) in Dec. The masers show substantial variability in flux density and velocity structure, most notably IRS~7, which shows a 30-fold brightening in a blueshifted component since 2022. This variability may set a floor on future astrometry improvements and especially measurements of radial acceleration.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.31766",
  "author_total": 9,
  "authors": [
    {
      "name": "Jeremy Darling"
    },
    {
      "name": "Jennie Paine"
    },
    {
      "name": "Matthew Hosek Jr."
    },
    {
      "name": "Shoko Sakai"
    },
    {
      "name": "Stefan Gillessen"
    },
    {
      "name": "Tatsuya Akiba-Lewis"
    },
    {
      "name": "Andrea Ghez"
    },
    {
      "name": "Frank Eisenhauer"
    },
    {
      "name": "Reinhard Genzel"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4n52ws4m1hrdr.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.31766",
  "fulltext_url": null,
  "id": "4n52ws4m1hrdr",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.31766",
  "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.GA"
    ],
    [
      "arxiv",
      "astro-ph.HE"
    ],
    [
      "arxiv",
      "astro-ph.SR"
    ],
    [
      "arxiv",
      "gr-qc"
    ],
    [
      "openalex",
      "3103|Astrophysical Phenomena and Observations"
    ]
  ],
  "openalex": "W7223697110",
  "pdf_url": "https://arxiv.org/pdf/2610.31766",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-22",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4n52ws4m1hrdr.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:15Z",
      "native_id": "2610.31766",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.31766"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    },
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "The Galactic Center Reference Frame: A 30-Year Solution",
  "title_text": "The Galactic Center Reference Frame: A 30-Year Solution",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:15Z",
  "url": "https://research.draconitic.com/paper/4n52ws4m1hrdr",
  "venue": "arXiv",
  "versions": []
}