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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"
  1. Konus-Wind observation of very bright GRB 081215A
  2. GRB 081222: Swift XRT refined analysis
  3. GRB081221: Fermi GBM observation
  4. Swift/UVOT observations of GRB 081221
  5. IPN triangulation of bright GRB 081215A
  6. GRB 081221: Swift-XRT Refined Analysis
  7. GRB 081221: pseudo-redshift (pz=0.7) from the spectral parameters of the prompt emission
  8. GRB 081222: Faulkes Telescope South observations
  9. GRB 081221: Gemini-N nIR imaging
  10. GRB081222, optical observation
  11. GRB081222: Swift/UVOT detection of an optical afterglow
  12. GRB081203A: BTA observation
  13. Konus-Wind observation of GRB 081221
  14. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  15. GRB081222: REM candidate afterglow
  16. GRB 081222: Swift detection of a burst with a bright optical afterglow
  17. GRB 081221: Enhanced Swift-XRT position
  18. GRB 081221: further NOT observations
  19. GRB 081221: NOT observations
  20. GRB 081221: Swift detection of a burst
  21. GRB 081217: Fermi GBM detection
  22. Modification of Swift/UVOT response to bright GRBs
  23. GRB081215A: Fermi-LAT observations
  24. GRB 081211B: Further Swift-XRT analysis
  25. GRB 081215B: Fermi GBM detection
  26. GRB 081216: Suzaku WAM observation of the prompt emission
  27. GRB 081216 : Fermi GBM observation
  28. GRB 081215A: Fermi GBM detection (correction to event fluence)
  29. GRB 081215A: Fermi GBM detection
  30. IPN localization of short hard GRB 081216
  31. GRB 081211B - possibly a short burst with extended emission
  32. GRB 081118: Zadko observations
  33. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  34. GRB 081215A: Gamma Repeater?
  35. GRB 0811215A: MASTER prompt optical observations
  36. GRB 081215A: Andromeda inside Fermi error box: MASTER observations
  37. GRB 0811215A: Andromeda inside Fermi error box: MASTER observations
  38. Possible GRB 081211B: Swift/UVOT Upper Limits
  39. GRB 081213: Fermi GBM detection
  40. GRB 081210: optical observations
  41. Possible GRB 081211B - Swift-XRT analysis
  42. GRB 081207: Fermi GBM detection
  43. GRB 081209: Fermi GBM detection
  44. Fermi Gamma-ray Burst Monitor trigger 250533995 is not a GRB
  45. GRB 081007: Detection of a Supernova
  46. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  47. GRB 081210: Xinglong TNT R band Upper Limits
  48. GRB 081210, SMARTS optical/IR observations
  49. GRB 081211: Swift-BAT refined analysis
  50. GRB 081211: Swift XRT refined analysis
  51. GRB 081211: Swift/UVOT detection of an optical afterglow
  52. GRB 081211: Enhanced Swift-XRT position
  53. GRB 081210: Swift/UVOT refined analysis
  54. GRB 081211: Swift detection of a burst
  55. GRB 081210: Swift-XRT refined analysis
  56. GRB081203B: optical observations
  57. GRB 081210: Enhanced Swift-XRT position
  58. GRB 081210: Swift-BAT refined analysis
  59. GRB 081210: Swift detection of a burst with optical afterglow
  60. Konus-Wind observation of GRB 081209
  61. IPN triangulation of short hard GRB 081209
  62. GRB 081203A: optical observations
  63. GRB 081206C: Fermi GBM detection
  64. Radio observation of GRB 081121 with ATCA
  65. Radio observation of GRB 081118 with ATCA
  66. GRB 081206B: Fermi GBM detection
  67. GRB 081206: Fermi GBM detection
  68. GRB 081128: afterglow observations
  69. GRB 081203B: Suzaku WAM observation of the prompt emission
  70. GRB 081203B: Additional Gemini imaging
  71. Radio observation of GRB 081109 with ATCA
  72. Radio observation of GRB 081104 with ATCA
  73. Radio observation of GRB 081029 with ATCA
  74. Radio observation of GRB 081008 with ATCA
  75. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  76. GRB 081203B: Gemini observations
  77. GRB 081128: optical observation in CrAO
  78. GRB081203A: Optical observations at Ishigaki
  79. GRB 081128: Optical afterglow observations
  80. GRB 081204: GROND Observations
  81. GRB081203B: optical observations
  82. Radio detection of GRB 081203B with the VLA
  83. GRB 081204: Magellan observations
  84. GRB081203A: Radio upper limit at 15 GHz
  85. GRB 081204B: Fermi GBM detection
  86. GRB 081204: Swift/UVOT Upper Limits
  87. GRB 081204: Swift XRT afterglow confirmation
  88. GRB081203A: MITSuME optical observation
  89. GRB 081203A: Optical observations of Xinglong TNT telescope
  90. GRB 081203A: Skynet/GORT Detections
  91. GRB 081204: Swift XRT afterglow candidate
  92. GRB081203A: optical observation
  93. GRB 081204 : a long GRB localized by INTEGRAL
  94. VLA Radio upper limit on GRB 081203A
  95. Swift-XRT observations of GRB 081203B
  96. Konus-Wind observation of GRB 081203A
  97. Konus-Wind observation of GRB 081203B
  98. GRB081203A: Swift-XRT refined analysis
  99. GRB 081203B: optical observations
  100. GRB 081203B: SDSS upper limits at the position of the optical afterglow

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