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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

33 results found.

  1. GRB 261010A: VLA radio observations
  2. GRB 261010A: LBT tentative near-infrared detection
  3. GRB 261010A: 10.4m GTC spectroscopy of the galaxy 2" from the afterglow
  4. GRB 250521D: SVOM/GRM analysis suggests a possible “long” duration type I burst
  5. GRB 211211A: observations with the 3.6m Devasthal Optical Telescope
  6. GRB 211211A: MMT/MMIRS Observations Indicate Fading of K-band Source
  7. GRB 211211A: TNG NIR observations
  8. GRB 211211A: Insight-HXMT/HE detection
  9. GRB 211211A - Gemini K-band detection
  10. GRB 211211A: SAO RAS optical observations
  11. GRB 211211A: AbAO optical observations
  12. GRB 211211A: GMG upper limit
  13. GRB 211211A: redshift estimation and SPI-ACS/INTEGRAL detection
  14. GRB 211211A: Very fast decay observed from CAFOS/2.2mCAHA
  15. GRB 211211A: Further observations from CAFOS/2.2m CAHA
  16. GRB 211211A: HCT and GIT optical follow up observations
  17. GRB 211211A: CALET Gamma-Ray Burst Monitor detection
  18. GRB 211211A: incorrect E_iso value in GCN 31221
  19. GRB 211211A: Swift/UVOT detection
  20. GRB 211211A: NOT optical spectroscopy
  21. GRB 211211A: Afterglow detection from CAFOS/2.2m CAHA
  22. GRB 211211A: MITSuME Akeno optical observation
  23. Swift GRB 211211A: Global MASTER-Net observations report
  24. GRB 211211A: LCO Optical Observations
  25. GRB 211211A: Nanshan/NEXT optical observations
  26. GRB 211211A: Swift-XRT refined Analysis
  27. GRB 211211A: Fermi GBM observation
  28. GRB 211211A: Swift-BAT refined analysis
  29. Fermi GRB 211211A: Global MASTER-Net observations report
  30. GRB 211211A: Enhanced Swift-XRT position
  31. GRB 211211A: KAIT Optical Afterglow Candidate
  32. GRB 211211A: Swift detection of a bright burst
  33. GRB 211211A: Fermi GBM Final Real-time Localization

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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