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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"

54 results found.

  1. GRB 250331C: Swift/UVOT Upper Limits
  2. LIGO/Virgo/KAGRA S250119ag: Updated Sky localization
  3. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  4. GRB 241006A: Swift/UVOT Upper Limits
  5. EXO 0748-676: Swift-BAT refined analysis
  6. Trigger 1236151: Swift detection of EXO 0748-676
  7. IceCube Alert 240229.66: Global MASTER-Net observations report
  8. Fermi trigger No 729914426: Global MASTER-Net observations report
  9. GRB 240102A: Swift/UVOT Upper Limits
  10. IceCube Alert 221210.36: Global MASTER-Net observations report
  11. IPN triangulation of GRB 211219A
  12. Swift GRB 210919A: Global MASTER-Net observations report
  13. GRB 210822A: Swift/UVOT Detection
  14. GRB 210305A: Swift/UVOT Upper Limits
  15. GRB 201227A: AGILE detection of a burst
  16. GRB 201020A: Swift/UVOT Observations
  17. GRB 200228B: Swift/UVOT Upper Limits
  18. GRB 190204A: Swift/UVOT Detection
  19. GRB 180618A: Swift/UVOT Detection
  20. GRB 180404A: Swift/UVOT Detection
  21. GRB 170111A: Swift/UVOT Upper Limits
  22. GRB 161117B: Swift/UVOT Upper Limits
  23. GRB 161022A: Swift/UVOT Upper Limits
  24. GRB 160716A: Swift/UVOT Detection
  25. Trigger 677981: Swift detection of IGRJ17091-3624
  26. GRB 150711A: Enhanced Swift-XRT position
  27. GRB 150424A: Swift-XRT refined Analysis
  28. Swift triggered on a source in Terzan 5 (trigger=637212)
  29. GRB 150403A: Swift/UVOT Detection
  30. GRB 140719A: Swift/UVOT Upper Limits
  31. GRB 140516A: Swift/UVOT Upper Limits
  32. GRB 140408A: Swift/UVOT Upper Limits
  33. GRB 131030A: Swift/UVOT Detection
  34. GRB 130609B: Swift/UVOT Observations
  35. GRB 120811C: MASTER-Tunka OT observations
  36. GRB 120324A: Swift/UVOT Upper Limits
  37. Swift J1822.3-1606: Transient Magnetar or Be X-ray Binary?
  38. Swift/UVOT Observations of GRB100814A - a clearer table.
  39. Swift/UVOT observations of GRB100814A
  40. GRB 090328: Fermi GBM Spectral Analysis
  41. GRB 090111: Swift UVOT Upper Limits
  42. Swift/UVOT observations of GRB080409
  43. GRB 080307: Swift/UVOT Upper Limits
  44. GRB 080303: Swift/UVOT follow-up of afterglow detection
  45. Further Retractions of previous Swift-BAT triggers
  46. Retractions of previous Swift-BAT triggers
  47. GRB 061217: ROTSE-III Optical Limits
  48. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  49. GRB060807 - SDSS Pre-burst Observations
  50. GRB060428A: Swift XRT Team refined analysis
  51. Optical Follow-up of GRB000529 Error Box
  52. X-ray Afterglow of GRB 000529
  53. New IPN localization of GRB000529
  54. IPN localization of GRB000529

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