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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"

27293 results found.

  1. GRB 090817: Liverpool Telescope Observations
  2. GRB 090817: Confirmation of the X-ray afterglow
  3. GRB 090815C: Swift refined analysis
  4. GRB 090817: Swift/UVOT Upper Limits
  5. GRB 090812: Konus-Wind and Swift/BAT joint spectral analysis
  6. GRB 090817: Swift-XRT observations
  7. GRB 090813: Suzaku WAM observation of the prompt emission
  8. GRB 090812: Suzaku WAM observation of the prompt emission
  9. VLA radio non-detection of GRB 090812
  10. GRB 090815B: Fermi GBM detection
  11. GRB 090815: Fermi GBM detection
  12. GRB 090813: CrAO optical obsevations
  13. GRB 090814B: Confirmation of the X-ray afterglow
  14. GRB 090814B: I-band observations from 1.23m CAHA telescope
  15. GRB 090814B: Swift/UVOT Upper Limits
  16. GRB 090814B: Liverpool Telescope Observations
  17. GRB 090814C: Fermi GBM detection
  18. GRB 090814B: Swift-XRT detection of a possible afterglow.
  19. GRB 090814A: Swift/UVOT Observations
  20. GRB 090814A: Swift-XRT Team Refined Analysis
  21. GRB 090814A, RIMOTS optical upper limits
  22. GRB 090814A: Swift-BAT refined analysis
  23. GRB090814A: VLT spectroscopy
  24. GRB 090814: Enhanced Swift-XRT position
  25. GRB 090814: GROND Detection of an Optical Afterglow Candidate
  26. GRB 090814: Swift detection of a burst
  27. GRB 090813: Fermi GBM observation
  28. GRB 090813: Swift-XRT refined analysis
  29. GRB 090813, Swift-BAT refined analysis
  30. Konus-Wind observations of GRB090813
  31. GRB090813: Swift/UVOT upper limits
  32. GRB 090813: Enhanced Swift-XRT position
  33. GRB 090813: Liverpool Telescope afterglow confirmation
  34. GRB 090813: Swift detection of a burst
  35. GRB 090812: WIRO NIR upper limit
  36. GRB 090812: Faulkes Telescope South Continued Optical Monitoring
  37. GRB 090812: RAPTOR detections during the burst
  38. GRB 090812: Swift XRT refined analysis
  39. GRB 090812, RIMOTS optical upper limits
  40. GRB 090812 Swift-BAT Refined Analysis
  41. GRB090812: Swift/UVOT observations
  42. GRB 090812: GROND Observations of the Optical/NIR Afterglow
  43. GRB 090812: Enhanced Swift-XRT position
  44. GRB 090812: Liverpool Telescope afterglow confirmation
  45. GRB 090812: Swift detection of a burst with an optical counterpart
  46. GRB 090807B: Fermi GBM detection
  47. GRB 090809B: Fermi GBM detection
  48. GRB 090809: Swift-XRT refined analysis
  49. GRB090809: Swift/UVOT observations
  50. GRB 090809: Enhanced Swift-XRT position
  51. GRB 090809: Swift-BAT refined analysis
  52. GRB 090809: Swift detection of a burst with a possible optical counterpart
  53. GRB 090807: Liverpool Telescope observations
  54. GRB 090807: Swift/UVOT Upper Limits
  55. GRB 090807: Swift-XRT refined analysis
  56. GRB 090807, Swift-BAT refined analysis
  57. GRB 090807: Enhanced Swift-XRT position
  58. GRB 090807, RIMOTS optical upper limits
  59. GRB 090807: Swift detection of a burst
  60. GRB 090802B: Fermi GBM detection
  61. GRB 090802: Fermi GBM detection
  62. GRB 090726: optical observation
  63. Swift-BAT trigger 358760 is most likely not a GRB
  64. Swift trigger 358760 is probably a noise event
  65. GRB 090709A : Quick look analysis of the Suzaku observation
  66. GRB 090728: Swift-BAT refined analysis
  67. GRB 090727: GRT Optical Observation
  68. GRB 090728: Swift XRT refined analysis
  69. GRB 090726: GRT Optical Observation
  70. GRB 090727: Swift/UVOT Upper Limits
  71. GRB 090728: Swift/UVOT Upper Limits
  72. GRB 090728: Enhanced Swift-XRT position
  73. GRB 090728, RIMOTS optical upper limits
  74. GRB 090728A: Faulkes Telescope North Optical Afterglow Candidate
  75. GRB 090728: Swift detection of a burst
  76. GRB 090727: Swift-BAT refined analysis
  77. GRB 090727: Swift-XRT refined analysis
  78. GRB 090727: Liverpool Telescope Afterglow Confirmation and Optical Flare
  79. GRB 090727: Enhanced Swift-XRT position
  80. GRB 090727: Liverpool Telescope possible OT candidate
  81. GRB 090727: Swift detection of a burst
  82. GRB090726: Swift/UVOT observations
  83. GRB 090726, Swift-BAT refined analysis
  84. GRB 090726: Afterglow candidate photometryfrom Crni Vrh
  85. GRB 090726: D50 optical observations
  86. GRB 090711: Fermi GBM detection
  87. GRB090726: 6-meter telescope redshift
  88. GRB 090726: Swift-XRT Team refined analysis
  89. GRB 090726: Enhanced Swift-XRT position
  90. GRB 090726: Swift/UVOT Finding Chart Observation
  91. GRB 090726: Swift-XRT position of probable counterpart
  92. GRB 090726: Swift detection of a burst
  93. Swift Trigger 358354 is not a GRB
  94. GRB 090720: Gemini-North Imaging and Optical Afterglow
  95. GRB 090720B: Fermi GBM detection
  96. Swift XRT and UVOT refned analysis of GRB 090720
  97. GRB 090709A: Swift XRT Timing Analysis
  98. GRB 090715B: VLA radio detection
  99. GRB 090720 Source found in ground processing of Swift-BAT data
  100. GRB 090717B: Fermi GBM detection

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