GCN Alert: Messaggio GCN inviato alle 2026-04-28 17:59:58:MS260428p Most probable sky location…

{
    "alert_type": "PRELIMINARY",
    "time_created": "2026-04-28T15:59:51Z",
    "superevent_id": "MS260428p",
    "urls": {
        "gracedb": "https://gracedb.ligo.org/superevents/MS260428p/view/"
    },
    "event": {
        "significant": true,
        "time": "2026-04-28T15:55:28.679Z",
        "far": 9.110699364861297e-14,
        "instruments": [
            "H1",
            "L1"
        ],
        "group": "CBC",
        "pipeline": "gstlal",
        "search": "MDC",
        "properties": {
            "HasNS": 1,
            "HasRemnant": 1,
            "HasMassGap": 0
        },
        "classification": {
            "BNS": 0.9999948944542763,
            "NSBH": 0,
            "BBH": 0,
            "Terrestrial": 5.105545723868371e-6
        },
        "duration": null,
        "central_frequency": null
    },
    "external_coinc": {
        "gcn_notice_id": 1461426950,
        "ivorn": "ivo://lvk.internal/Fermi#MDC-test_event_2026-04-28T15:55:32.469Z",
        "observatory": "Fermi",
        "search": "MDC",
        "time_difference": 3.79,
        "time_coincidence_far": 5.6335184428841735e-18,
        "time_sky_position_coincidence_far": 8.351236485365366e-17
    }
}