GCN Alert: Messaggio GCN inviato alle 2026-04-21 20:59:49:MS260421s Most probable sky location…

{
    "alert_type": "PRELIMINARY",
    "time_created": "2026-04-21T18:59:42Z",
    "superevent_id": "MS260421s",
    "urls": {
        "gracedb": "https://gracedb.ligo.org/superevents/MS260421s/view/"
    },
    "event": {
        "significant": true,
        "time": "2026-04-21T18:59:32.586Z",
        "far": 5.176954877338635e-16,
        "instruments": [
            "H1",
            "L1",
            "V1"
        ],
        "group": "CBC",
        "pipeline": "gstlal",
        "search": "MDC",
        "properties": {
            "HasNS": 1,
            "HasRemnant": 1,
            "HasMassGap": 0
        },
        "classification": {
            "BNS": 0.9999998181083838,
            "NSBH": 0,
            "BBH": 0,
            "Terrestrial": 1.8189161613866663e-7
        },
        "duration": null,
        "central_frequency": null
    },
    "external_coinc": {
        "gcn_notice_id": 1460833191,
        "ivorn": "ivo://lvk.internal/SNEWS#MDC-test_event_2026-04-21T18:59:33.107Z",
        "observatory": "SNEWS",
        "search": "MDC",
        "time_difference": 0.52,
        "time_coincidence_far": null,
        "time_sky_position_coincidence_far": null
    }
}