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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"

17373 results found.

  1. GRB 981226
  2. GRB 981226 optical observations
  3. GRB 981220:Optical Observations
  4. GRB981226, BeppoSAX Christmas GRB
  5. GRB 981226 optical observations
  6. GRB 981220, radio observations
  7. GRB 981220
  8. GRB 980326/Host Galaxy
  9. BeppoSAX NFI Observation of GRB980425
  10. GRB980329 R,I flux calibration and R,I,K upper limits
  11. GRB980425 Optical Follow-up
  12. GRB970508 optical observations
  13. GRB980519, Optical Observations
  14. GRB 980703 (NFI observations)
  15. GRB980703 optical photometry
  16. GRB980703 optical observations
  17. GRB980703: Radio transient
  18. GRB980703 Transient Optical Follow-Up
  19. GRB980703: LOTIS observation at early times
  20. BeppoSAX NFI observations of GRB 980703
  21. GRB980703 optical followup
  22. SGR1627-41
  23. Radio observations of SGRs
  24. SGR1900+14 field optical observations
  25. GRB 980613 Near-IR observations
  26. GRB 980613: Optical transient and its host galaxy
  27. SGR1627-41, Refined IPN annulus location
  28. GRB 980613: Detection of the probable host galaxy
  29. SGR 1627-41
  30. GRB 980613 Optical Observations
  31. GRB 980613 optical observations
  32. Discovery of a new SGR source, SGR1627-41
  33. GRB980613 Optical Observations
  34. GRB980613 observations from Palomar
  35. GRB980613 Near Infra-Red Observations
  36. GRB971214 Secondary Standards
  37. GRB980519 Secondary Standards
  38. GRB 980519 Optical Observations
  39. GRB 980519
  40. GRB980519 optical observations
  41. GRB 980519 Optical Observations
  42. GRB980519 Optical Observations
  43. GRB 980519 Optical Observations
  44. GRB980515, BeppoSAX IAUC to be submitted
  45. BSAX Observations of GRB980425 field
  46. SAX J0840.7+2248 Optical Observations
  47. GRB980425: optical obs.
  48. GRB980425: Radio Observations
  49. report on BSAX observations of GRB980425
  50. GRB980326 X-ray Observations
  51. GRB980326, optical observations
  52. GRB980326, optical observations
  53. GRB980326 IPN annulus
  54. GRB980329 Keck K-band observations
  55. GRB980326 optical observations
  56. GRB980329 optical observations
  57. GRB980329 VLA observations
  58. GRB980329 optical observations
  59. GRB980326 optical observations
  60. Optical Observations of GRB 970508
  61. Near-IR follow-up on GRB 971227
  62. Optical Observations of the GRB 971227 field
  63. Optical Observations on GRB 971227
  64. GRB971227: Plaskett R-band observations
  65. GRB 971227: Optical clarifications
  66. GRB971227: Further CAHA R-band images
  67. GRB971227: LOTIS observations
  68. GRB 971227: CAHA R-band images
  69. GRB971214: Optical Observations and Calibrations
  70. GRB 971214: Optical Observations
  71. Radio Observations of GRB 971214 at the VLA
  72. GRB 971024: KPNO Optical Observations
  73. GRB 970828: Palomar Observations

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