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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"

21 results found.

  1. GRB 201209A: Mondy optical observations, afterglow confirmation
  2. IceCube-201209A : MAXI/GSC upper limit
  3. GRB 201209A: Insight-HXMT/HE detection
  4. IceCube-201209A: Upper limits from Insight-HXMT/HE observations
  5. IceCube-201209: No significant detection in HAWC
  6. IceCube-201209A: No Candidate Counterparts from the Zwicky Transient Facility
  7. IceCube-201209A: Upper limits from a search for additional neutrino events in IceCube
  8. GRB 201209A: Swift/UVOT Upper Limits
  9. IceCube-201209A: Upper limits from Fermi-GBM Observations
  10. Fermi-LAT Gamma-ray Observations of IceCube-201209A
  11. IceCube-201209A: No neutrino counterpart candidates in ANTARES search
  12. GRB 201209A: Swift-BAT refined analysis
  13. IceCube-201209A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  14. GRB 201209A: Swift-XRT refined Analysis
  15. GRB 201209A: Xinglong-2.16m likely optical afterglow detection
  16. IceCube-201209A: IceCube observation of a high-energy neutrino candidate event
  17. GRB 201209A: AstroSat CZTI detection
  18. GRB 201209A: Enhanced Swift-XRT position
  19. GRB 201209A: KAIT Optical Upper Limit
  20. GRB 201209A: FRAM-Auger optical limit
  21. GRB 201209A: Swift detection of a burst

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