Optical alerts

Optical alert with crossmatch gcn events

View the source on GitHub

Properties

* = required

Name	Type	Description
$schema
data	object	Data container for targets and photometry

Properties from all of the following:

These properties are inherited using the allOf syntax. In order to validate, all of the following schemas must be individually valid, based on their respective properties. See allOf for more information.

Name		Description
Alert.schema.json		core schema object (click to expand)
Reporter.schema.json		core schema object (click to expand)

Locally defined sub-schemas

These sub-schemas are defined locally within the same .schema.json file as the current schema definition.

Name	Type	Description
data	object
target	object
photometry	object

Example

{
  "$schema": "https://gcn.nasa.gov/schema/v6.3.0/gcn/notices/boom/alert.schema.json",
  "alert_datetime": "2025-11-30T10:28:57Z",
  "mission": "Boom",
  "data": {
    "targets": [
      {
        "event_name": "ZTF25acffkdr",
        "ra": 150.175649,
        "dec": 15.2832185,
        "classification_scores": {
          "Type II": 0.9
        },
        "gcn_crossmatch": [
          {
            "ref_type": "GW",
            "ref_instrument": "LVK",
            "ref_ID": "S251117bs"
          }
        ]
      }
    ],
    "photometry": [
      {
        "event_name": "ZTF25acffkdr",
        "observation_start": "2025-11-27T14:03:06.509Z",
        "telescope": "Asteroid Terrestrial-impact Last Alert System",
        "instrument": "ATLAS",
        "filter": "atlaso",
        "mag_system": "AB",
        "limiting_mag": 19.53
      },
      {
        "event_name": "ZTF25acffkdr",
        "observation_start": "2025-11-28T10:07:08.003Z",
        "telescope": "Palomar 1.2m Oschin",
        "instrument": "ZTF",
        "filter": "ztfg",
        "mag": 18.1,
        "mag_error": 0.02,
        "mag_system": "AB",
        "limiting_mag": 20.48
      },
      {
        "event_name": "ZTF25acffkdr",
        "observation_start": "2025-11-28T11:10:01.998Z",
        "telescope": "Palomar 1.2m Oschin",
        "instrument": "ZTF",
        "filter": "ztfr",
        "mag": 18.37,
        "mag_error": 0.03,
        "mag_system": "AB",
        "limiting_mag": 20.58
      },
      {
        "event_name": "ZTF25acffkdr",
        "observation_start": "2025-11-29T03:25:56.064Z",
        "telescope": "Liverpool Telescope",
        "instrument": "IOO",
        "filter": "sdssg",
        "mag": 17.78,
        "mag_error": 0.03,
        "mag_system": "AB",
        "limiting_mag": 20.96
      },
      {
        "event_name": "ZTF25acffkdr",
        "observation_start": "2025-11-29T03:27:29.117Z",
        "telescope": "Liverpool Telescope",
        "instrument": "IOO",
        "filter": "sdssr",
        "mag": 18.08,
        "mag_error": 0.04,
        "mag_system": "AB",
        "limiting_mag": 21.2
      },
      {
        "event_name": "ZTF25acffkdr",
        "observation_start": "2025-11-29T03:30:57.600Z",
        "telescope": "Liverpool Telescope",
        "instrument": "IOO",
        "filter": "sdssz",
        "mag": 18.68,
        "mag_error": 0.09,
        "mag_system": "AB",
        "limiting_mag": 20.39
      },
      {
        "event_name": "ZTF25acffkdr",
        "observation_start": "2025-11-30T10:28:56.997Z",
        "telescope": "Palomar 1.2m Oschin",
        "instrument": "ZTF",
        "filter": "ztfr",
        "mag": 17.98,
        "mag_error": 0.05,
        "mag_system": "AB",
        "limiting_mag": 19.49
      }
    ]
  }
}