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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"

21767 results found.

  1. GRB090904B: REM observations
  2. GRB 090904B: Swift detection of a burst
  3. GRB 090904A: ROTSE-III Optical Limits
  4. GRB 090904: Swift detection of a burst
  5. GRB 090902B: Swift/UVOT refined analysis
  6. GRB 090902B: GROND NIR Afterglow Observations
  7. GRB 090902B: Enhanced Swift-XRT position
  8. GRB090902B: Swift/UVOT observations
  9. GRB 090902B: Swift/XRT Afterglow Candidate
  10. GRB 090902B: Fermi LAT detection
  11. GRB 090831C: GROND upper limits
  12. Konus-Wind observations of GRB 090831A
  13. Swift Trigger 361477, called GRB090831B, is probably not real.
  14. GRB090831C: Swift/UVOT upper limits
  15. GRB 090831B: MITSuME optical upper limits
  16. GRB 090831C: Enhanced Swift-XRT position
  17. GRB 090831C: Swift detection of a burst
  18. GRB 090831B, RIMOTS optical upper limits
  19. GRB 090831B: Swift detection of a possible burst
  20. GRB 090827: Swift XRT and UVOT observations
  21. GRB 090828: Fermi GBM detection
  22. GRB 090817 - TLS Observations
  23. GRB 090823: Swift XRT possible detection of the X-ray afterglow
  24. GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
  25. GRB 090820: MASTER-Net optical polarization observations
  26. GRB 090820: Fermi GBM Detection of a bright burst.
  27. GRB 090817: optical upper limit
  28. GRB 090817: Confirmation of the X-ray afterglow
  29. GRB 090817: Swift/UVOT Upper Limits
  30. GRB 090812: Konus-Wind and Swift/BAT joint spectral analysis
  31. GRB 090817: Swift-XRT observations
  32. GRB 090814A: optical observations
  33. GRB 090813: Suzaku WAM observation of the prompt emission
  34. GRB 090812: Suzaku WAM observation of the prompt emission
  35. VLA radio non-detection of GRB 090812
  36. GRB 090813: CrAO optical obsevations
  37. GRB090814A: NOT optical follow-ups
  38. GRB 090814B: I-band observations from 1.23m CAHA telescope
  39. GRB 090814B: Swift/UVOT Upper Limits
  40. GRB 090814B: Swift-XRT detection of a possible afterglow.
  41. GRB 090814A: Swift/UVOT Observations
  42. GRB 090814A, RIMOTS optical upper limits
  43. GRB090814A: VLT spectroscopy
  44. GRB 090814: Enhanced Swift-XRT position
  45. GRB 090814: GROND Detection of an Optical Afterglow Candidate
  46. GRB 090814: Swift detection of a burst
  47. GRB090813: Swift/UVOT upper limits
  48. GRB 090813: Enhanced Swift-XRT position
  49. GRB 090813: P60 Optical Afterglow Confirmation
  50. GRB 090813: Swift detection of a burst
  51. GRB 090812: Faulkes Telescope South Continued Optical Monitoring
  52. GRB 090812: RAPTOR detections during the burst
  53. GRB 090812, RIMOTS optical upper limits
  54. GRB 090812 Swift-BAT Refined Analysis
  55. GRB090812: Swift/UVOT observations
  56. GRB 090812: GROND Observations of the Optical/NIR Afterglow
  57. GRB 090812: Enhanced Swift-XRT position
  58. GRB 090812: P60 Confirmation of Optical Afterglow
  59. GRB 090812: Swift detection of a burst with an optical counterpart
  60. GRB 090807B: Fermi GBM detection
  61. GRB 090809: Further NOT optical observations
  62. VLA radio upper limit on GRB 090809
  63. GRB 090809: WHT observations
  64. GRB 090809B: Fermi GBM detection
  65. GRB090809: Swift/UVOT observations
  66. GRB 090809: Enhanced Swift-XRT position
  67. GRB 090809: afterglow confirmation at the NOT
  68. GRB 090809: Swift detection of a burst with a possible optical counterpart
  69. GRB 090807: MITSuME optical upper limit
  70. GRB 090807: Swift/UVOT Upper Limits
  71. GRB 090807, Swift-BAT refined analysis
  72. GRB 090807: Enhanced Swift-XRT position
  73. GRB 090807, RIMOTS optical upper limits
  74. GRB 090807: Swift detection of a burst
  75. IPN Triangulation and Konus-Wind observaions of GRB090727B
  76. GRB 090726: optical observation
  77. Swift trigger 358760 is probably a noise event
  78. GRB 090717A: Suzaku WAM observation of the prompt emission
  79. GRB 090727: GRT Optical Observation
  80. GRB 090726: GRT Optical Observation
  81. GRB 090727: Swift/UVOT Upper Limits
  82. GRB 090728: Swift/UVOT Upper Limits
  83. GRB 090728: Enhanced Swift-XRT position
  84. GRB 090728, RIMOTS optical upper limits
  85. GRB 090728: Swift detection of a burst
  86. GRB 090727: Swift-BAT refined analysis
  87. GRB 090727: Enhanced Swift-XRT position
  88. GRB 090715B: Late-time Lick 3m observations
  89. GRB 090727: Swift detection of a burst
  90. GRB090726: Swift/UVOT observations
  91. GRB 090726, Swift-BAT refined analysis
  92. GRB 090726: Enhanced Swift-XRT position
  93. GRB 090726: optical transient candidate
  94. Konus-Wind and Konus-RF observations of GRB 090719
  95. Konus-RF and Konus-Wind observations of GRB 090718B
  96. Konus-Wind observations of bright hard GRB 090720B
  97. GRB 090720B: Fermi GBM detection
  98. Swift XRT and UVOT refned analysis of GRB 090720
  99. GRB 090715B: VLA radio detection
  100. GRB 090720 Source found in ground processing of Swift-BAT data

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