{
  "abstract": "We report the detection of photometric variability in the directly imaged super-Jupiter β Pictoris b ( β Pic b). Using JWST NIRCam dual-band coronagraphic imaging, we conducted a 16 hr continuous photometric monitoring campaign in the F210M and F410M filters. We developed and validated a time-series photometry framework that combines point-spread function subtraction, principal component analysis for systematic noise removal, and injection-and-recovery tests to confirm signal fidelity. Both light curves show consistent sinusoidal variability at ∼5 σ and ≫5 σ significance in the F210M and F410M bands, respectively. A joint sinusoidal fit yields a rotation period of P rot = 9.00 ± 0.13 hr and variability amplitudes of 0.85% ± 0.07% and 0.89% ± 0.04% in F210M and F410M, respectively. The near-identical amplitudes and periods in both bands confirm a common astrophysical origin in a heterogeneous atmosphere. Combining P rot with the previously measured projected rotational velocity, we constrain the line-of-sight spin axis inclination of β Pic b. The result favors an equator-on viewing geometry, consistent with line-of-sight spin–orbit alignment: the planetary spin axis, orbital plane, debris disk, and stellar equator are all mutually aligned. This stands in sharp contrast to the large obliquities of wide-separation companions that are likely formed via gravitational fragmentation. Together with the system’s young age, this observation provides independent dynamical evidence that β Pic b formed via core accretion. This result constitutes the first detection of rotational modulation in a close-in, high-contrast exoplanet that likely formed via core accretion, demonstrating that time-series coronagraphic imaging with JWST opens a powerful new window onto the rotation, atmospheric dynamics, and spin–orbit architecture of this population.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 31,
  "authors": [
    {
      "name": "Yifan Zhou"
    },
    {
      "name": "Beth Biller"
    },
    {
      "name": "Aarynn Carter"
    },
    {
      "name": "Marshall Perrin"
    },
    {
      "name": "Michael Poon"
    },
    {
      "name": "Genaro Suárez"
    },
    {
      "name": "Ben J. Sutlieff Ben J. Sutlieff"
    },
    {
      "name": "Johanna Vos"
    },
    {
      "name": "Jason Wang"
    },
    {
      "name": "William Balmer"
    },
    {
      "name": "Marta Bryan"
    },
    {
      "name": "Anthony Boccaletti"
    },
    {
      "name": "Julien Girard"
    },
    {
      "name": "Eileen Gonzales"
    },
    {
      "name": "Jens Kammerer"
    },
    {
      "name": "Jarron Leisenring"
    },
    {
      "name": "Paulina. Palma-Bifani"
    },
    {
      "name": "Kevin Wagner"
    },
    {
      "name": "Dániel Apai"
    },
    {
      "name": "Mickäel Bonnefoy"
    },
    {
      "name": "Brendan Bowler"
    },
    {
      "name": "Kyle Franson"
    },
    {
      "name": "Pengyu Liu"
    },
    {
      "name": "Marcio Meléndez"
    },
    {
      "name": "Stanimir Metchev"
    },
    {
      "name": "Simon Petrus"
    },
    {
      "name": "Laurent Pueyo"
    },
    {
      "name": "Isabel Rebollido"
    },
    {
      "name": "Andrew Skemer"
    },
    {
      "name": "Xianyu Tan"
    },
    {
      "name": "Niall Whiteford"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dpx2gpv7e9mtb.bib",
  "cited_by": 0,
  "doi": "10.3847/1538-3881/ae8bab",
  "fulltext_url": null,
  "id": "dpx2gpv7e9mtb",
  "issns": [
    "0004-6256",
    "1538-3881"
  ],
  "landing_url": "https://hal.science/hal-05845904v1",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.phys"
    ],
    [
      "hal",
      "1.phys.astr"
    ],
    [
      "openalex",
      "3103|Stellar, planetary, and galactic studies"
    ]
  ],
  "openalex": "W7202393801",
  "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-3881/ae8bab/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-13",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/dpx2gpv7e9mtb.ris",
  "sources": [
    {
      "first_seen": "2026-10-31T12:20:56Z",
      "native_id": "hal-05845904",
      "source": "hal",
      "url": "https://hal.science/hal-05845904v1"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Stellar, planetary, and galactic studies",
      "subfield": "stellar"
    }
  ],
  "title": "Photometric Variability and Rotation of β Pictoris b from JWST NIRCam Coronagraphic Imaging",
  "title_text": "Photometric Variability and Rotation of β Pictoris b from JWST NIRCam Coronagraphic Imaging",
  "type": "peer-reviewed",
  "updated_at": "2026-11-01T12:20:46Z",
  "url": "https://research.draconitic.com/paper/dpx2gpv7e9mtb",
  "venue": "The Astronomical Journal",
  "versions": []
}