Skip to main content
New! Circulars over Kafka, Heartbeat Topic, and Schema v4.1.0. See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').

8 results found.

  1. GRB 191220A: Swift-BAT refined analysis
  2. GRB 191220A: Swift/UVOT Upper Limits
  3. GRB 191220A: AbAO optical observations
  4. GRB 191220A: Swift-XRT refined Analysis
  5. GRB 191220A: Enhanced Swift-XRT position
  6. GRB 191220A: SAO RAS possible OT detection
  7. GRB 191220A: Swift detection of a burst
  8. GRB 191220A: Prompt enhanced Swift-XRT position

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov