{
  "source_frames": 57,
  "method": "Temporal median star model subtraction in the star-aligned sequence, fixed star-core mask, object centring, cross-tail matched profile, and coherent linear-ridge search across all source frames.",
  "nucleus_pixel": [
    282.0,
    244.0
  ],
  "tail_axis_image_angle_deg": 186.75,
  "star_mask_fraction_percent": 41.424325659806996,
  "candidate": {
    "velocity_px_per_frame": 0.31249999999999994,
    "middle_radius_px": 67.75,
    "objective": 0.731326209861256,
    "support_above_1sigma_percent": 36.84210526315789,
    "median_zscore": 0.622704051219543,
    "positions_px": [
      59.0,
      59.3125,
      59.625,
      59.9375,
      60.25,
      60.5625,
      60.875,
      61.1875,
      61.5,
      61.8125,
      62.125,
      62.4375,
      62.75,
      63.0625,
      63.375,
      63.6875,
      64.0,
      64.3125,
      64.625,
      64.9375,
      65.25,
      65.5625,
      65.875,
      66.1875,
      66.5,
      66.8125,
      67.125,
      67.4375,
      67.75,
      68.0625,
      68.375,
      68.6875,
      69.0,
      69.3125,
      69.625,
      69.9375,
      70.25,
      70.5625,
      70.875,
      71.1875,
      71.5,
      71.8125,
      72.125,
      72.4375,
      72.75,
      73.0625,
      73.375,
      73.6875,
      74.0,
      74.3125,
      74.625,
      74.9375,
      75.25,
      75.5625,
      75.875,
      76.1875,
      76.5
    ]
  },
  "speed": {
    "cadence_seconds_per_source_frame": 547.8856780515773,
    "pixel_scale_arcsec": 52.43357361852693,
    "projected_km_per_pixel": 27053.695244512306,
    "projected_speed_km_s": 15.43073692668093,
    "deprojected_speed_km_s": 29.04700186577631
  },
  "geometry": {
    "source": "https://ssd.jpl.nasa.gov/api/horizons.api",
    "reference_frame": "J2000 ecliptic, heliocentric",
    "comet": {
      "command": "90004923;",
      "jd_tdb": 2460949.930555556,
      "time": "A.D. 2025-Oct-01 10:20:00.0000",
      "position_au": [
        -0.1998815643868184,
        -0.3027472256385531,
        -0.1494756396947516
      ],
      "velocity_au_per_day": [
        -0.0167587946505697,
        0.03420211120159539,
        -0.007610132306607167
      ]
    },
    "observer": {
      "command": "-144",
      "jd_tdb": 2460949.930555556,
      "time": "A.D. 2025-Oct-01 10:20:00.0000",
      "position_au": [
        0.4278817821783759,
        -0.03563202635632285,
        0.05216659975407761
      ],
      "velocity_au_per_day": [
        0.01452457855998439,
        0.02491563739478294,
        0.0064009212003214
      ]
    },
    "comet_heliocentric_distance_au": 0.3923665241527595,
    "observer_range_au": 0.7114049070032177,
    "tail_to_line_of_sight_angle_deg": 32.088827155438366,
    "sky_projection_factor": 0.5312333781636065,
    "deprojection_factor": 1.8824118383841935
  },
  "confidence": "low",
  "validation": {
    "candidate_is_unambiguous": false,
    "reason": "The ridge is weak and supported above one robust sigma in only part of the sequence. Residual stellar structure and changing tail morphology can imitate a moving knot.",
    "strongest_unmasked_contaminant_px_per_frame": 0.66,
    "contaminant_interpretation": "Residual star-field motion in the object-centred coordinate system; excluded by the fixed star mask."
  },
  "sources": [
    "local-evaluation/final/cloud-corrected/stars-expanded.mp4",
    "web/data/example-analysis.json",
    "local-evaluation/astrometry-mini/data/comet-identification.json",
    "https://ssd.jpl.nasa.gov/api/horizons.api"
  ]
}