{
  "abstract": "A growing number of transiting exoplanets exhibit spectroscopic evidence that their leading and trailing limbs differ. Interpreting these observations is now the limiting step. The standard approach of fitting limb-resolved transit depths results in highly anticorrelated transit depths, and treating them as independent measurements can result in strongly biased (3 σ ) retrieved molecular abundances. We present an inference framework that avoids these correlations by using the temporal signature of limb asymmetry instead. This wavelength-dependent shift in mid-transit time, or “time-shift spectrum,” carries the limb-asymmetry information, is measurable from existing light curves with a spherically symmetric transit model, and is uncorrelated with the spherically averaged transit depth. Simultaneously fitting the resulting transmission and time-shift spectrum with an independent atmospheric column for each limb enables the retrieval of limb-resolved properties from two independent measurements. We demonstrate that this approach reduces the mean squared error on the retrieved molecular abundances by factors of ∼30–50 relative to the next best of the alternative approaches currently adopted in the field, and improves retrieved abundance precision by ∼3–6× . We apply the framework to WASP-94A b and present its panchromatic limb-resolved spectrum, spanning 0.8–5 μ m and combining NIRISS/SOSS and NIRSpec/G395H observations. The planet’s morning limb remains aerosol-obscured across this entire range, while its evening limb constrains the abundances of H ₂ O, CO ₂ , CO, and H ₂ S. We measure a limb-to-limb temperature difference of 415 ± 58 K at 1 mbar. This limb-resolved analysis finds [M/H] = +0.32 − 0.11 + 0.11 and C/O = 0.724 − 0.013 + 0.013 , consistent with the host star.",
  "abstract_shown": true,
  "affiliations": [
    "Arizona State University",
    "Johns Hopkins University"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Sagnick Mukherjee",
      "orcid": "0000-0003-1622-1302"
    },
    {
      "affs": [
        0
      ],
      "name": "Luis Welbanks",
      "orcid": "0000-0003-0156-4564"
    },
    {
      "affs": [
        1
      ],
      "name": "Guangwei Fu",
      "orcid": "0000-0002-3263-2251"
    },
    {
      "affs": [
        1
      ],
      "name": "David K. Sing",
      "orcid": "0000-0001-6050-7645"
    },
    {
      "affs": [
        0
      ],
      "name": "Michael R. Line",
      "orcid": "0000-0002-2338-476X"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8weje3mbfvhtj.bib",
  "cited_by": 0,
  "doi": "10.3847/2041-8213/aeb6af",
  "fulltext_url": null,
  "id": "8weje3mbfvhtj",
  "issns": [
    "2041-8213",
    "2041-8205"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/2041-8213/aeb6af",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "feed-journal",
      "astronomy/general"
    ]
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  "pdf_url": "https://iopscience.iop.org/article/10.3847/2041-8213/aeb6af/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/8weje3mbfvhtj.ris",
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    {
      "first_seen": "2026-11-04T12:20:45Z",
      "native_id": "10.3847/2041-8213/aeb6af",
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      "url": "https://iopscience.iop.org/article/10.3847/2041-8213/aeb6af"
    },
    {
      "first_seen": "2026-11-04T12:20:54Z",
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      "url": "https://iopscience.iop.org/article/10.3847/2041-8213/aeb6af"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "journal-openalex:3103|Stellar, planetary, and galactic studies",
      "subfield": "stellar"
    }
  ],
  "title": "A New Method for Constraining 3D Exoplanet Atmospheres: Application to WASP-94A b’s Panchromatic Spectrum",
  "title_text": "A New Method for Constraining 3D Exoplanet Atmospheres: Application to WASP-94A b’s Panchromatic Spectrum",
  "type": "peer-reviewed",
  "updated_at": "2026-11-06T00:21:00Z",
  "url": "https://research.draconitic.com/paper/8weje3mbfvhtj",
  "venue": "The Astrophysical Journal Letters",
  "versions": [
    {
      "doi": "10.48550/arxiv.2610.22271",
      "pid": "den2mjbepraaf",
      "relation": "preprint",
      "title": "A New Method for Constraining 3D Exoplanet Atmospheres: Application to WASP-94A b's Panchromatic Spectrum",
      "venue": "arXiv"
    }
  ]
}