{
  "abstract": "We present a multi-band optical variability study of the $γ$-ray emitting high-synchrotron-peaked blazar 1ES~0647+250 during its enhanced optical activity in 2020. The analysis utilizes 107 epochs of high-precision $B$, $V$, and $R$-band photometry obtained with the 75 cm telescope at the Vainu Bappu Observatory, combined with high-cadence $z_g$ and $z_r$ survey data from the Zwicky Transient Facility. The combined light curves reveal coherent variability across all optical filters, with the source reaching a peak $R$-band magnitude of 15.74 mag. We calculated the variability amplitude, finding the highest intrinsic variability in the B- band. Spectral analysis using color--magnitude diagrams reveals a statistically significant ``Bluer-When-Brighter'' trend, supported by a Pearson correlation coefficient of $r = 0.68$ ($p < 0.001$) for the (V$-$R) index. Furthermore, the discrete correlation function analysis indicates a near-zero time lag between the $V$ and $R$ bands, suggesting simultaneous emission within the observational cadence. The observed spectral hardening is consistent with synchrotron-dominated optical emission, likely associated with enhanced particle acceleration within the jet during the active phase of 1ES~0647+250.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.27630",
  "author_total": 7,
  "authors": [
    {
      "name": "K. Subbu Ulaganatha Pandian"
    },
    {
      "name": "C. S. Stalin"
    },
    {
      "name": "S. Muneer"
    },
    {
      "name": "S. Umayal"
    },
    {
      "name": "Aditi Agarwal"
    },
    {
      "name": "Amit Kumar Mandal"
    },
    {
      "name": "B. Natarajan"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7fng27pdydxpk.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.27630",
  "fulltext_url": null,
  "id": "7fng27pdydxpk",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.27630",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "arxiv",
      "astro-ph.HE"
    ],
    [
      "openalex",
      "3106|Astrophysics and Cosmic Phenomena"
    ]
  ],
  "openalex": "W7214160709",
  "pdf_url": "https://arxiv.org/pdf/2609.27630",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/7fng27pdydxpk.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:56Z",
      "native_id": "2609.27630",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.27630"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "Multi-Band Optical Variability Characteristics of the $γ$-ray emitting blazar 1ES 0647+250 during its 2020 flare",
  "title_text": "Multi-Band Optical Variability Characteristics of the γ-ray emitting blazar 1ES 0647+250 during its 2020 flare",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:56Z",
  "url": "https://research.draconitic.com/paper/7fng27pdydxpk",
  "venue": "arXiv",
  "versions": []
}