GCN Alert: Messaggio GCN inviato alle 2025-12-18 11:03:52:MS251218j Most probable sky location…

{
    "alert_type": "PRELIMINARY",
    "time_created": "2025-12-18T10:03:45Z",
    "superevent_id": "MS251218j",
    "urls": {
        "gracedb": "https://gracedb.ligo.org/superevents/MS251218j/view/"
    },
    "event": {
        "significant": true,
        "time": "2025-12-18T10:01:25.646Z",
        "far": 6.786496426516116e-14,
        "instruments": [
            "H1",
            "V1"
        ],
        "group": "CBC",
        "pipeline": "gstlal",
        "search": "MDC",
        "properties": {
            "HasNS": 1,
            "HasRemnant": 1,
            "HasMassGap": 0
        },
        "classification": {
            "BNS": 0.9999835696735185,
            "NSBH": 0,
            "BBH": 0,
            "Terrestrial": 1.6430326481417913e-5
        },
        "duration": null,
        "central_frequency": null
    },
    "external_coinc": {
        "gcn_notice_id": 1450087306,
        "ivorn": "ivo://lvk.internal/fsc#MDC-test_event_2025-12-18T10:01:28.824Z",
        "observatory": "SVOM",
        "search": "MDC",
        "time_difference": 3.18,
        "time_coincidence_far": 4.196368604676061e-18,
        "time_sky_position_coincidence_far": 6.232598290636817e-18
    }
}