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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.

Lucene Examples (click to copy):

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

25 results found.

  1. GRB 241217A / EP241217B: radio detection with the VLA
  2. GRB 241217a/EP241217b: ATCA Radio Detection
  3. GRB 241217A/EP241217b: continued SOAR observations
  4. GRB 241217A / EP241217b: Non-detection in ATCA Radio Follow-up Observations
  5. GRB 241217A/EP241217b: SOAR afterglow detection
  6. GRB 241217A/EP241217b: tentative VLT spectroscopic redshift z=1.879
  7. GRB 241217a/EP241217B: 1.6m Mephisto optical upper limits
  8. GRB 241217A / EP241217B: GRANDMA/T1MPicduMidi optical upperlimits
  9. EP 241217a: NIR detection with P200/WIRC
  10. EP 241217a: Possible J-band detection with WINTER
  11. GRB 241217A/EP241217B: Fermi-GBM Sub-Threshold Detection
  12. GRB 241217A / EP241217b: Nanshan/HMT optical upper limit
  13. GRB 241217A: refined SVOM/MXT data analysis. Long lasting X-ray emission.
  14. GRB 241217A / EP241217b: NOT optical upper limits
  15. GRB 241217A/EP241217b: REM optical/NIR upper limits
  16. GRB 241217a: Liverpool Telescope optical follow-up
  17. EP241217a: Xinglong optical follow-up observations
  18. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  19. GRB 241217A: GMG Optical Upper Limit
  20. GRB 241217A : SVOM/VT optical afterglow detection
  21. GRB 241217A: Swift-XRT afterglow detection
  22. GRB 241217A: LCO optical upper limit
  23. GRB 241217A: GRANDMA/TAROT optical upperlimits
  24. EP241217a: Swift-XRT Detection
  25. GRB 241217A : SVOM/ECLAIRs,GRM,MXT detection of a long burst with a bright X-ray afterglow candidate

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