{
  "abstract": "We present visible-to-infrared (0.5-5.56 μm) observations of the interstellar comet 3I/ATLAS obtained with the Moons and Jupiter Imaging Spectrometer aboard the Jupiter Icy Moons Explorer spacecraft between 2025 November 2 and 25, shortly after perihelion. The fluorescence emission from H 2 O at 2.7 μm and CO 2 at 4.3 μm is detected at heliocentric distances of 1.36-1.68 au. A weak dust-scattered continuum is identified from which we determine the spectral slope, with values ranging from ∼15% per 100 nm in the 0.65-0.9 μm region to 1%-3% per 100 nm from 0.9 to 2.6 μm. Spatially resolved measurements show that the radial distributions of H 2 O and CO 2 species are consistent with release in the near-nucleus environment. We derive H 2 O production rates that decreased from 8 × 10 28 s -1 to 4 × 10 28 s -1 over the period November 2-25, while the CO 2 /H 2 O ratio remained nearly constant at ∼10%. The heliocentric evolution of the CO 2 production rate indicates activity controlled by solar heating. Combined with published CO measurements and the low gas expansion velocities, our analyses support a scenario in which CO 2 plays a major role in driving the activity of 3I/ATLAS near perihelion. In addition, broad emission features are identified in the 3.2-3.6 μm region that cannot be explained by the fluorescence of common cometary CH-bearing volatiles. Their spectral characteristics are consistent with aliphatic C-H functional groups and provide tentative evidence for the release of complex organic material from dust grains in the coma.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 19,
  "authors": [
    {
      "name": "D. Bockelée-Morvan"
    },
    {
      "name": "F Poulet"
    },
    {
      "name": "R.Y. Langevin"
    },
    {
      "name": "Benoît Seignovert"
    },
    {
      "name": "C. Leyrat"
    },
    {
      "name": "G. Piccioni"
    },
    {
      "name": "C Royer"
    },
    {
      "name": "S. Rodriguez"
    },
    {
      "name": "E. D’aversa"
    },
    {
      "name": "R. Brunetto"
    },
    {
      "name": "J. Carter"
    },
    {
      "name": "T. Cavalié"
    },
    {
      "name": "M. de Sanctis"
    },
    {
      "name": "E. Lellouch"
    },
    {
      "name": "A. Migliorini"
    },
    {
      "name": "C. Pilorget"
    },
    {
      "name": "E. Quirico"
    },
    {
      "name": "S. Robert"
    },
    {
      "name": "F. Tosi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/33m4rymtebrv0.bib",
  "cited_by": 0,
  "doi": "10.3847/2041-8213/ae8a47",
  "fulltext_url": null,
  "id": "33m4rymtebrv0",
  "issns": [
    "2041-8205",
    "2041-8213"
  ],
  "landing_url": "https://hal.science/hal-05753495v1",
  "language": "en",
  "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": [
    [
      "hal",
      "0.sdu"
    ],
    [
      "hal",
      "1.sdu.astr"
    ],
    [
      "hal",
      "2.sdu.astr.ep"
    ],
    [
      "openalex",
      "3103|Astro and Planetary Science"
    ]
  ],
  "openalex": "W7213761319",
  "pdf_url": "https://hal.science/hal-05753495/document",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-17",
  "publisher": "Bristol : IOP Publishing",
  "ris": "https://research.draconitic.com/paper/33m4rymtebrv0.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:36Z",
      "native_id": "hal-05753495",
      "source": "hal",
      "url": "https://hal.science/hal-05753495v1"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "hal:2.sdu.astr.ep",
      "subfield": "planetary"
    },
    {
      "field": "earth",
      "origin": "hal:0.sdu",
      "subfield": "general"
    }
  ],
  "title": "Near-perihelion Activity and Composition of 3I/ATLAS from JUICE/MAJIS Observations",
  "title_text": "Near-perihelion Activity and Composition of 3I/ATLAS from JUICE/MAJIS Observations",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:36Z",
  "url": "https://research.draconitic.com/paper/33m4rymtebrv0",
  "venue": "The Astrophysical Journal Letters",
  "versions": []
}