GCN Alert: Messaggio GCN inviato alle 2026-04-21 17:59:57:MS260421p Most probable sky location…

{
    "alert_type": "PRELIMINARY",
    "time_created": "2026-04-21T15:59:49Z",
    "superevent_id": "MS260421p",
    "urls": {
        "gracedb": "https://gracedb.ligo.org/superevents/MS260421p/view/"
    },
    "event": {
        "significant": true,
        "time": "2026-04-21T15:59:32.075Z",
        "far": 6.786496426516116e-14,
        "instruments": [
            "H1",
            "V1"
        ],
        "group": "CBC",
        "pipeline": "gstlal",
        "search": "MDC",
        "properties": {
            "HasNS": 1,
            "HasRemnant": 1,
            "HasMassGap": 0
        },
        "classification": {
            "BNS": 0.9999958799328944,
            "NSBH": 0,
            "BBH": 0,
            "Terrestrial": 4.1200671057167535e-6
        },
        "duration": null,
        "central_frequency": null
    },
    "external_coinc": {
        "gcn_notice_id": 1460822391,
        "ivorn": "ivo://lvk.internal/Fermi#MDC-test_event_2026-04-21T15:59:33.139Z",
        "observatory": "Fermi",
        "search": "MDC",
        "time_difference": 1.06,
        "time_coincidence_far": 4.196368604676061e-18,
        "time_sky_position_coincidence_far": 4.1459733049343954e-17
    }
}