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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').

16 results found.

  1. GRB 211227A: Konus-Wind detection and joint Konus-Wind+Swift-BAT spectral analysis
  2. GRB 211227A: Lijiang 2.4m Telescope Optical Observations
  3. GRB 211227A: Gemini South Optical Observations
  4. GRB 211227A: Deep early CAHA 2.2m/CAFOS observation
  5. GRB 211227A: CALET Gamma-Ray Burst Monitor detection
  6. GRB 211227A: Swift/UVOT Upper Limits
  7. GRB 211227A: Swift-XRT refined Analysis
  8. GRB 211227A: Swift-BAT refined analysis
  9. GRB 211227A: A possible short GRB with extended emission at z = 0.228?
  10. GRB 211227A: Liverpool Telescope upper limits
  11. GRB 211227A: Enhanced Swift-XRT position
  12. GRB 211227A: LCO Optical Observations
  13. GRB 211227A: Nanshan/NEXT optical observations and host galaxy candidate
  14. GRB 211227A: MAXI/GSC detection
  15. GRB 211227A: BOOTES-2/TELMA optical upper limit
  16. GRB 211227A: Swift detection of a burst


Download all Circulars as a .tar.gz archive:
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