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GCN Classic Migrations

Since the launch of the modernized GCN in 2022, the GCN Team has been gradually migrating interfaces and services from GCN Classic to the New GCN.

GCN Circulars Archive

The GCN Classic Circulars archive, processing, and distribution service was migrated to the new GCN on April 17, 2023. All legacy user subscriptions and submission privileges were transferred.

Notices

All legacy GCN Classic Notice types and formats are available via self service subscription Kafka and email. Legacy socket and email distribution of Notices continues through GCN Classic, but users are encouraged to move to the new system. To unsubscribe from your GCN Classic legacy subscriptions, please contact us.

VOEvent Transport Protocol

VOEvent Transport Protocol distribution of GCN Classic Notices was retired on April 6, 2026. VOEvent format Notices remain available via Kafka and email.

Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
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Get involved on GitHub.

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