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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').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

36 results found.

  1. Konus-Wind detection of GRB 210401A
  2. GRB 210104A: LBT observations
  3. ZTF21aagwbjr/AT2021buv: ZTF discovery of a fast optical transient likely associated with GRB 210104A
  4. GRB 210104A: 3.6m DOT optical upper limit
  5. GRB 210104A: Late-time CAHA 2.2m detection
  6. GRB 210104A: JCMT SCUBA-2 sub-mm observations
  7. GRB 210104A: AstroSat CZTI detection
  8. GRB 210104A: AROMA-N Optical Afterglow Detection
  9. GRB 210104A: Mondy optical observations, light curve
  10. GRB 210104A: Assy continued optical observations, correction to GCN circ. 29265
  11. GRB 210104A: SAO RAS optical observations
  12. GRB 210104A: GMG observations
  13. GRB 210104A: SARA-KP 0.9m Optical Afterglow Detection
  14. GRB 210104A: iTelescope optical upper limit
  15. GRB 210104A: CALET Gamma-Ray Burst Monitor detection
  16. GRB 210104A: Assy continued optical observations
  17. GRB 210104A: early ATLAS detections of the bright afterglow
  18. GRB 210104A: Swift-XRT refined Analysis
  19. Konus-Wind detection of GRB 210104A
  20. GRB 210104A: 1.3m DFOT Optical Afterglow Detection
  21. GRB 210104A: DOAO optical afterglow observations
  22. GRB 210104A: Nanshan/NEXT optical powerlaw decay
  23. GRB 210104A: Swift-BAT refined analysis
  24. GRB 210104A: MASTER OT rebrightening detection
  25. GRB 210104A: Swift/UVOT Detection
  26. GRB 210104A: Fermi GBM detection
  27. GRB 210104A: Enhanced Swift-XRT position
  28. GRB 210104A: MITSuME Ishigaki optical observation
  29. Fermi GRB 210104A: Global MASTER-Net observations report
  30. GRB 210104A: Assy optical observations
  31. GRB 210104A: MITSuME Akeno optical observation
  32. GRB 210104A: BOOTES-4/MET early optical afterglow detection
  33. GRB 210104A: GWAC-F60A optical afterglow observations
  34. GRB 210104A: BALROG localization (Fermi Trigger 631452424 / GRB 210104477)
  35. GRB 210104A: Swift detection of a burst with a bright optical counterpart
  36. GRB 210104A: Fermi GBM Final Real-time Localization

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