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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"

32 results found.

  1. GRB 201029A: Swift-XRT refined Analysis
  2. GRB 170714A: NOEMA non-detection of the Bastille Day Burst
  3. GRB 170714A: Bastille Day Burst: ULGRB or RTDE?
  4. GRB 130925A: HST imaging
  5. GRB 130925A: Possible signatures of binary nature in the afterglow - Request for observations
  6. GRB 130925A: 3mm observations with CARMA
  7. GRB 130925A/Sw J0244-2609: mm observations at PdBI
  8. NuSTAR observations of GRB 130925A
  9. GRB 130925A: continuing Swift/XRT monitoring
  10. IPN Observations of GRB 130925A
  11. Fermi LAT Upper Limits on GRB 130925A
  12. GRB 130925A: Swift/UVOT Detection of the Host Galaxy
  13. GRB 130925A: Swift/UVOT Upper Limits
  14. GRB 130925A: sub-mm non-detection with SMA
  15. GRB 130925A: optical upper limit
  16. GRB 130925A: Continued RATIR Optical and NIR Observations
  17. GRB 130925A: Fermi GBM Detection
  18. Konus-Wind observation of GRB 130925A
  19. Observation of possible GRB/TDE 130925A by INTEGRAL/SPI-ACS: three activity episodes
  20. GRB 130925A: RATIR Optical and NIR Observations
  21. GRB 130925A Swift-BAT refined analysis
  22. GRB 130925A: Historical non-detection from Rosat-HRI
  23. Fermi GBM detection of GRB 130925A and a possible precursor
  24. GRB 130925A: Swift-XRT refined Analysis
  25. GRB 130925A: Initial Similarities to Swift J1644+57
  26. GRB 130925A: TAROT La Silla observatory optical observations
  27. GRB 130925A: Enhanced Swift-XRT position
  28. GRB 130925A: VLT/X-shooter redshift
  29. GRB 130925A: VLT/UVES observations
  30. GRB 130925A: MAXI/GSC detection
  31. GRB 130925A: GROND afterglow candidate
  32. GRB 130925A: Swift detection of a burst

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