GCN Alert: Messaggio GCN inviato alle 2026-07-21 06:13:33:

{
    "alert_type": "RETRACTION",
    "time_created": "2026-07-21T04:13:33Z",
    "superevent_id": "MS260721d",
    "urls": {
        "gracedb": "https://gracedb.ligo.org/superevents/MS260721d/view/"
    },
    "event": null,
    "external_coinc": null
}