{
  "id": "hyg41-sky-v1",
  "source": "HYG Database v4.1 / astronexus",
  "source_url": "https://github.com/astronexus/HYG-Database",
  "license": "CC BY-SA 4.0",
  "license_url": "https://creativecommons.org/licenses/by-sa/4.0/",
  "attribution": "HYG Database / astronexus. Selected and transformed into the frozen STAR-02 letter assignment for PCDVR.",
  "source_sha256": "2fb1b6ff082a7daf129bbb4bc8cb46ed9152ce73b1d47587163070e7ecfc43ef",
  "coordinates": {
    "ra_unit": "hours",
    "dec_unit": "degrees"
  },
  "field": {
    "anchor": {
      "catalog_index": 109145,
      "hyg_id": "109146",
      "hip": "109492",
      "hd": "210745",
      "hr": "8465",
      "proper": "",
      "bf": "21Zet Cep",
      "constellation": "Cep",
      "display_name": "21Zet Cep",
      "ra_hours": 22.180908,
      "dec_deg": 58.201261,
      "distance_pc": 256.4103,
      "magnitude": 3.39,
      "x_pc": 120.077626,
      "y_pc": -61.940455,
      "z_pc": 217.924077
    },
    "candidate_pool_size": 72,
    "metadata": {
      "radius_limit_deg": 12,
      "pool_size": 72,
      "center_unit": [
        0.4683028163950965,
        -0.2415681465256037,
        0.8499042903413331
      ],
      "east_unit": [
        0.4584383049093227,
        0.8887262348956887,
        0
      ],
      "north_unit": [
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        0.38962868219924157,
        0.5269370904191458
      ]
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  },
  "projection": {
    "pcdvr_3d_mean": [
      4.115384615384615,
      3.5384615384615383,
      1.5
    ],
    "pcdvr_3d_to_2d_basis": [
      [
        0.44001799503261624,
        -0.26586065553255034
      ],
      [
        -0.23754258557758012,
        0.8866831197371929
      ],
      [
        0.8660009723346701,
        0.3783003529114417
      ]
    ],
    "equation": "projected = (pcdvr_xyz - mean) @ basis",
    "tangent_plane": {
      "radius_limit_deg": 12,
      "pool_size": 72,
      "center_unit": [
        0.4683028163950965,
        -0.2415681465256037,
        0.8499042903413331
      ],
      "east_unit": [
        0.4584383049093227,
        0.8887262348956887,
        0
      ],
      "north_unit": [
        -0.7553322399767451,
        0.38962868219924157,
        0.5269370904191458
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  "ideal_transform": {
    "scale": 0.02957795958521318,
    "rotation": [
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        -0.7756847335226701
      ],
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        -0.6311205860846755
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    ],
    "translation": [
      -0.009614249667103805,
      0.01876474776922059
    ],
    "reflected": true,
    "equation": "mapped = scale * (source @ rotation) + translation"
  },
  "letters": {
    "A": {
      "hip": "108924",
      "hyg_id": "108578",
      "name": "18    Cep",
      "ra_hours": 22.064709,
      "dec_deg": 63.11992,
      "mag": 5.26,
      "con": "Cep",
      "pcdvr_address": [
        2,
        2,
        0
      ]
    },
    "B": {
      "hip": "106227",
      "hyg_id": "105885",
      "name": "HIP 106227",
      "ra_hours": 21.51647,
      "dec_deg": 60.459432,
      "mag": 5.53,
      "con": "Cep",
      "pcdvr_address": [
        2,
        5,
        0
      ]
    },
    "C": {
      "hip": "108165",
      "hyg_id": "107822",
      "name": "13    Cep",
      "ra_hours": 21.914766,
      "dec_deg": 56.611227,
      "mag": 5.74,
      "con": "Cep",
      "pcdvr_address": [
        2,
        4,
        3
      ]
    },
    "D": {
      "hip": "109746",
      "hyg_id": "109400",
      "name": "HIP 109746",
      "ra_hours": 22.230475,
      "dec_deg": 63.162337,
      "mag": 6.13,
      "con": "Cep",
      "pcdvr_address": [
        3,
        2,
        0
      ]
    },
    "E": {
      "hip": "107418",
      "hyg_id": "107075",
      "name": "10Nu  Cep",
      "ra_hours": 21.75748,
      "dec_deg": 61.120806,
      "mag": 4.25,
      "con": "Cep",
      "pcdvr_address": [
        3,
        5,
        0
      ]
    },
    "F": {
      "hip": "107723",
      "hyg_id": "107380",
      "name": "HIP 107723",
      "ra_hours": 21.821948,
      "dec_deg": 61.27276,
      "mag": 6.18,
      "con": "Cep",
      "pcdvr_address": [
        5,
        5,
        0
      ]
    },
    "G": {
      "hip": "112635",
      "hyg_id": "112276",
      "name": "HIP 112635",
      "ra_hours": 22.812291,
      "dec_deg": 62.93841,
      "mag": 6.07,
      "con": "Cep",
      "pcdvr_address": [
        5,
        0,
        0
      ]
    },
    "H": {
      "hip": "109592",
      "hyg_id": "109246",
      "name": "HIP 109592",
      "ra_hours": 22.20056,
      "dec_deg": 60.759095,
      "mag": 5.37,
      "con": "Cep",
      "pcdvr_address": [
        5,
        3,
        0
      ]
    },
    "I": {
      "hip": "108772",
      "hyg_id": "108427",
      "name": "14    Cep",
      "ra_hours": 22.034604,
      "dec_deg": 58.000366,
      "mag": 5.55,
      "con": "Cep",
      "pcdvr_address": [
        4,
        4,
        2
      ]
    },
    "J": {
      "hip": "110504",
      "hyg_id": "110158",
      "name": "HIP 110504",
      "ra_hours": 22.385283,
      "dec_deg": 55.96323,
      "mag": 6.44,
      "con": "Cep",
      "pcdvr_address": [
        6,
        4,
        3
      ]
    },
    "K": {
      "hip": "107586",
      "hyg_id": "107243",
      "name": "12    Cep",
      "ra_hours": 21.790362,
      "dec_deg": 60.692689,
      "mag": 5.53,
      "con": "Cep",
      "pcdvr_address": [
        4,
        5,
        0
      ]
    },
    "L": {
      "hip": "110103",
      "hyg_id": "109757",
      "name": "25    Cep",
      "ra_hours": 22.303505,
      "dec_deg": 62.804388,
      "mag": 5.75,
      "con": "Cep",
      "pcdvr_address": [
        4,
        2,
        0
      ]
    },
    "M": {
      "hip": "109005",
      "hyg_id": "108659",
      "name": "20    Cep",
      "ra_hours": 22.083469,
      "dec_deg": 62.785671,
      "mag": 5.27,
      "con": "Cep",
      "pcdvr_address": [
        4,
        3,
        0
      ]
    },
    "N": {
      "hip": "110497",
      "hyg_id": "110151",
      "name": "HIP 110497",
      "ra_hours": 22.383383,
      "dec_deg": 57.284612,
      "mag": 6.18,
      "con": "Cep",
      "pcdvr_address": [
        5,
        3,
        3
      ]
    },
    "O": {
      "hip": "110498",
      "hyg_id": "110153",
      "name": "HIP 110498",
      "ra_hours": 22.383475,
      "dec_deg": 62.419357,
      "mag": 6.04,
      "con": "Cep",
      "pcdvr_address": [
        5,
        2,
        0
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    },
    "P": {
      "hip": "109017",
      "hyg_id": "108671",
      "name": "19    Cep",
      "ra_hours": 22.085775,
      "dec_deg": 62.279814,
      "mag": 5.07,
      "con": "Cep",
      "pcdvr_address": [
        2,
        2,
        1
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    "Q": {
      "hip": "111362",
      "hyg_id": "111013",
      "name": "HIP 111362",
      "ra_hours": 22.561281,
      "dec_deg": 56.624737,
      "mag": 5.72,
      "con": "Lac",
      "pcdvr_address": [
        6,
        3,
        3
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    },
    "R": {
      "hip": "111247",
      "hyg_id": "110900",
      "name": "HIP 111247",
      "ra_hours": 22.538529,
      "dec_deg": 54.037032,
      "mag": 6.41,
      "con": "Lac",
      "pcdvr_address": [
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        3,
        5
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    },
    "S": {
      "hip": "109585",
      "hyg_id": "109239",
      "name": "HIP 109585",
      "ra_hours": 22.199116,
      "dec_deg": 59.084579,
      "mag": 6.29,
      "con": "Cep",
      "pcdvr_address": [
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        3,
        2
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    },
    "T": {
      "hip": "105949",
      "hyg_id": "105608",
      "name": "HIP 105949",
      "ra_hours": 21.457025,
      "dec_deg": 59.750075,
      "mag": 6.11,
      "con": "Cep",
      "pcdvr_address": [
        2,
        5,
        1
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    },
    "U": {
      "hip": "110538",
      "hyg_id": "110192",
      "name": "3Bet Lac",
      "ra_hours": 22.392675,
      "dec_deg": 52.229046,
      "mag": 4.42,
      "con": "Lac",
      "pcdvr_address": [
        6,
        4,
        5
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    },
    "V": {
      "hip": "107259",
      "hyg_id": "106916",
      "name": "Mu  Cep",
      "ra_hours": 21.725127,
      "dec_deg": 58.780046,
      "mag": 4.23,
      "con": "Cep",
      "pcdvr_address": [
        4,
        5,
        1
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    },
    "W": {
      "hip": "110316",
      "hyg_id": "109970",
      "name": "HIP 110316",
      "ra_hours": 22.344311,
      "dec_deg": 50.980814,
      "mag": 6.4,
      "con": "Lac",
      "pcdvr_address": [
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        3,
        7
      ]
    },
    "X": {
      "hip": "105091",
      "hyg_id": "104753",
      "name": "HIP 105091",
      "ra_hours": 21.288553,
      "dec_deg": 58.611485,
      "mag": 6.42,
      "con": "Cep",
      "pcdvr_address": [
        2,
        7,
        0
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    },
    "Y": {
      "hip": "111795",
      "hyg_id": "111443",
      "name": "HIP 111795",
      "ra_hours": 22.64386,
      "dec_deg": 56.795632,
      "mag": 5.11,
      "con": "Lac",
      "pcdvr_address": [
        7,
        2,
        3
      ]
    },
    "Z": {
      "hip": "107197",
      "hyg_id": "106854",
      "name": "HIP 107197",
      "ra_hours": 21.712603,
      "dec_deg": 59.270844,
      "mag": 6.1,
      "con": "Cep",
      "pcdvr_address": [
        6,
        6,
        0
      ]
    }
  }
}