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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"

24 results found.

  1. GRB 260924A: Near-infrared detection with MDM/MIRAGE
  2. GRB 260924A: COLIBRÍ optical observations
  3. GRB 260924A: Second-epoch J-band upper limit from the SYSU 80 cm infrared telescope
  4. Konus-Wind detection of GRB 260924A
  5. GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations
  6. GRB 260924A: Optical follow-up observations with Kinder
  7. GRB 260924A: Ondrejov D50 optical afterglow detection
  8. GRB 260924A: SVOM/GRM observation
  9. GRB 260924A: 2.2m CAHA spectroscopic redshift z = 3.51
  10. GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
  11. GRB 260924A: Swift/UVOT Detection
  12. GRB 260924A: GROWTH-India Telescope optical observations
  13. GRB 260924A: Swift-BAT refined analysis
  14. GRB 260924A: NuSTAR detection of prompt emission
  15. GRB 260924A: Swift/UVOT Upper Limits
  16. GRB 260924A: Swift-XRT refined Analysis
  17. GRB 260924A: Fermi GRB Observation
  18. GRB 260924A: Fermi-LAT detection of a bright burst
  19. GRB 260924A: AstroSat CZTI detection
  20. GRB 260924A: NOT optical counterpart confirmation
  21. GRB 260924A: detection of a bright optical afterglow by the 1.5m OSN telescope
  22. GRB 260924A: Enhanced Swift-XRT position
  23. GRB 260924A: Swift detection of a burst
  24. GRB 260924A: Fermi GBM Final Real-time Localization

Advanced

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