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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"

42831 results found.

  1. GRB 081221: Swift-XRT Refined Analysis
  2. GRB 081221: pseudo-redshift (pz=0.7) from the spectral parameters of the prompt emission
  3. GRB 081222: Faulkes Telescope South observations
  4. GRB 081221: Gemini-N nIR imaging
  5. GRB081222: Swift/UVOT detection of an optical afterglow
  6. GRB081203A: BTA observation
  7. Konus-Wind observation of GRB 081221
  8. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  9. GRB081222: REM candidate afterglow
  10. GRB 081222: Swift detection of a burst with a bright optical afterglow
  11. GRB 081221: Enhanced Swift-XRT position
  12. GRB 081221: further NOT observations
  13. GRB 081221: NOT observations
  14. GRB 081221: Swift detection of a burst
  15. GRB 081217: Fermi GBM detection
  16. Modification of Swift/UVOT response to bright GRBs
  17. GRB081215A: Fermi-LAT observations
  18. GRB 081211B: Further Swift-XRT analysis
  19. GRB 081215B: Fermi GBM detection
  20. GRB 081216: Suzaku WAM observation of the prompt emission
  21. GRB 081216 : Fermi GBM observation
  22. GRB 081215A: Fermi GBM detection
  23. IPN localization of short hard GRB 081216
  24. GRB 081211B - possibly a short burst with extended emission
  25. GRB 081118: Zadko observations
  26. GRB 081213: Fermi GBM detection
  27. Possible GRB 081211B - Swift-XRT analysis
  28. GRB 081207: Fermi GBM detection
  29. GRB 081209: Fermi GBM detection
  30. GRB 081007: Detection of a Supernova
  31. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  32. GRB 081210, SMARTS optical/IR observations
  33. GRB 081211: Swift XRT refined analysis
  34. GRB 081211: Swift/UVOT detection of an optical afterglow
  35. GRB 081211: Enhanced Swift-XRT position
  36. GRB 081210: Swift/UVOT refined analysis
  37. GRB 081211: Swift detection of a burst
  38. GRB 081210: Swift-XRT refined analysis
  39. GRB081203B: optical observations
  40. GRB 081210: Enhanced Swift-XRT position
  41. GRB 081210: Swift-BAT refined analysis
  42. GRB 081210: Swift detection of a burst with optical afterglow
  43. Konus-Wind observation of GRB 081209
  44. IPN triangulation of short hard GRB 081209
  45. GRB 081203A: optical observations
  46. GRB 081206C: Fermi GBM detection
  47. Radio observation of GRB 081121 with ATCA
  48. Radio observation of GRB 081118 with ATCA
  49. GRB 081206B: Fermi GBM detection
  50. GRB 081206: Fermi GBM detection
  51. GRB 081128: afterglow observations
  52. GRB 081203B: Suzaku WAM observation of the prompt emission
  53. Radio observation of GRB 081109 with ATCA
  54. Radio observation of GRB 081104 with ATCA
  55. Radio observation of GRB 081029 with ATCA
  56. Radio observation of GRB 081008 with ATCA
  57. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  58. GRB 081203B: Gemini observations
  59. GRB 081128: optical observation in CrAO
  60. GRB081203A: Optical observations at Ishigaki
  61. GRB 081128: Optical afterglow observations
  62. GRB 081204: GROND Observations
  63. Radio detection of GRB 081203B with the VLA
  64. GRB 081204: Magellan observations
  65. GRB 081204B: Fermi GBM detection
  66. GRB 081204: Swift/UVOT Upper Limits
  67. GRB 081204: Swift XRT afterglow confirmation
  68. GRB081203A: MITSuME optical observation
  69. GRB 081203A: Optical observations of Xinglong TNT telescope
  70. GRB 081203A: Skynet/GORT Detections
  71. GRB 081204: Swift XRT afterglow candidate
  72. GRB081203A: optical observation
  73. GRB 081204 : a long GRB localized by INTEGRAL
  74. VLA Radio upper limit on GRB 081203A
  75. Swift-XRT observations of GRB 081203B
  76. Konus-Wind observation of GRB 081203A
  77. Konus-Wind observation of GRB 081203B
  78. GRB081203A: Swift-XRT refined analysis
  79. Swift/UVOT detection of GRB081203B
  80. GRB 081203B: Swift-XRT candidate afterglow.
  81. GRB 081203A: optical observations
  82. Swift UVOT observations of GRB 081203A
  83. GRB 081203B: Naming correction for burst detected in Swift-BAT slew data
  84. GRB081203A: Swift/UVOT grism redshift
  85. GRB 081203A: Burst detection from Swift-BAT slew data
  86. GRB 081203A: Swift-BAT refined analysis
  87. GRB 081203: Enhanced Swift-XRT position
  88. GRB 081130B: MASTER prompt optical observations
  89. GRB 081203: Swift detection of a burst with a bright optical counterpart
  90. GRB 081130B: Fermi GBM detection
  91. GRB 081130: Fermi GBM detection
  92. Swift Trigger 335971: Swift/UVOT Observations
  93. GRB 081126: Fermi GBM detection
  94. VLA Radio upper limit on GRB 081126
  95. GRB 081129: Fermi GBM detection
  96. GRB 081128A: optical observations
  97. Swift Trigger 335971 is probably not a real source
  98. Trigger 335971: Swift possible detection of a burst
  99. GRB081128: Swift/UVOT Upper Limits
  100. SGR 1806-20: Fermi GBM detection.

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