GCN Alert: Messaggio GCN inviato alle 2025-12-18 15:08:22:MS251218n Most probable sky location…

{
    "alert_type": "PRELIMINARY",
    "time_created": "2025-12-18T14:08:16Z",
    "superevent_id": "MS251218n",
    "urls": {
        "gracedb": "https://gracedb.ligo.org/superevents/MS251218n/view/"
    },
    "event": {
        "significant": true,
        "time": "2025-12-18T13:58:41.077Z",
        "far": 9.110699364861297e-14,
        "instruments": [
            "H1",
            "L1"
        ],
        "group": "CBC",
        "pipeline": "gstlal",
        "search": "MDC",
        "properties": {
            "HasNS": 1,
            "HasRemnant": 1,
            "HasMassGap": 0
        },
        "classification": {
            "BNS": 0.999994022660751,
            "NSBH": 0,
            "BBH": 0,
            "Terrestrial": 5.977339249019484e-6
        },
        "duration": null,
        "central_frequency": null
    },
    "external_coinc": {
        "gcn_notice_id": 1450101539,
        "ivorn": "ivo://lvk.internal/fsc#MDC-test_event_2025-12-18T13:58:41.623Z",
        "observatory": "SVOM",
        "search": "MDC",
        "time_difference": 0.55,
        "time_coincidence_far": 5.6335184428841735e-18,
        "time_sky_position_coincidence_far": 1.0898712762174568e-15
    }
}