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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"

19862 results found.

  1. GRB 090102: Swift detection of a burst with an optical counterpart
  2. GRB 090102: TAROT Calern observatory optical observations
  3. GRB 081230: GROND confirmation of the afterglow
  4. GRB081230: Swift-XRT refined analysis
  5. GRB 081230 Swift/UVOT Observations
  6. GRB 081230: Enhanced Swift-XRT position
  7. GRB 081230: Swift detection of a burst
  8. GRB 081228, Swift-BAT refined analysis
  9. VLA radio detection of GRB 081221
  10. GRB 081228: Swift/UVOT Upper Limits
  11. GRB 081228: Swift-XRT Team refined analysis
  12. GRB 081228: detection by GROND
  13. GRB 081228: Enhanced Swift-XRT position
  14. GRB 081228: TAROT Calern observatory optical observations
  15. GRB 081228: Swift detection of a burst
  16. VLA radio observation of GRB 081221
  17. GRB 081226B: Swift XRT and UVOT upper limits
  18. GRB 081226: Swift-XRT refined analysis
  19. GRB 081226A: Swift UVOT Upper Limits
  20. GRB 081226: GROND afterglow candidate
  21. GRB 081226: ROTSE-III Optical Limits
  22. GRB 081226: Swift detection of a possible short-hard burst
  23. GRB 080810: optical observations
  24. GRB 081211B: optical observations
  25. GRB 081224: Swift-XRT observation
  26. GRB 081222: MITSuME optical observation
  27. GRB 081221: GROND observations
  28. VLA radio upper limit on GRB 081222
  29. GRB 081221: Probable host galaxy in Keck imaging
  30. GRB 081222, Swift-BAT refined analysis
  31. GRB081222 optical limit by "Pi of the Sky"
  32. Konus-Wind observation of very bright GRB 081215A
  33. GRB 081222: Swift XRT refined analysis
  34. IPN triangulation of bright GRB 081215A
  35. GRB 081222: Faulkes Telescope South observations
  36. GRB 081221: Gemini-N nIR imaging
  37. GRB081222, optical observation
  38. GRB081203A: BTA observation
  39. Konus-Wind observation of GRB 081221
  40. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  41. GRB081222: REM candidate afterglow
  42. GRB 081222: Swift detection of a burst with a bright optical afterglow
  43. GRB 081221: Enhanced Swift-XRT position
  44. GRB 081221: further NOT observations
  45. GRB 081221: NOT observations
  46. GRB 081221: Swift detection of a burst
  47. GRB 081118: Zadko observations
  48. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  49. GRB 0811215A: MASTER prompt optical observations
  50. GRB 081215A: Andromeda inside Fermi error box: MASTER observations
  51. GRB 0811215A: Andromeda inside Fermi error box: MASTER observations
  52. Possible GRB 081211B: Swift/UVOT Upper Limits
  53. Possible GRB 081211B - Swift-XRT analysis
  54. GRB 081207: Fermi GBM detection
  55. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  56. GRB 081210, SMARTS optical/IR observations
  57. GRB 081211: Enhanced Swift-XRT position
  58. GRB 081211: Swift detection of a burst
  59. GRB081203B: optical observations
  60. GRB 081210: Enhanced Swift-XRT position
  61. GRB 081210: Swift detection of a burst with optical afterglow
  62. IPN triangulation of short hard GRB 081209
  63. GRB 081203A: optical observations
  64. GRB 081128: afterglow observations
  65. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  66. GRB 081128: optical observation in CrAO
  67. GRB081203A: Optical observations at Ishigaki
  68. GRB 081204: GROND Observations
  69. Radio detection of GRB 081203B with the VLA
  70. GRB081203A: Radio upper limit at 15 GHz
  71. GRB 081204B: Fermi GBM detection
  72. GRB 081204: Swift/UVOT Upper Limits
  73. GRB 081204: Swift XRT afterglow confirmation
  74. GRB081203A: MITSuME optical observation
  75. GRB081203A: optical observation
  76. VLA Radio upper limit on GRB 081203A
  77. GRB 081203B: optical observations
  78. Swift/UVOT detection of GRB081203B
  79. GRB 081203B: Swift-XRT candidate afterglow.
  80. GRB 081203A: optical observations
  81. GRB 081203: Enhanced Swift-XRT position
  82. GRB 081130B: MASTER prompt optical observations
  83. GRB081203: optical observation
  84. GRB 081203: Swift detection of a burst with a bright optical counterpart
  85. Swift Trigger 335971: Swift/UVOT Observations
  86. GRB 081126: afterglow photometry
  87. VLA Radio upper limit on GRB 081126
  88. GRB 081130: MASTER VWF prompt optical observations Fermi GRB
  89. GRB 081128A: optical observations
  90. Trigger 335971: Swift possible detection of a burst
  91. GRB081128: Swift/UVOT Upper Limits
  92. GRB 081128: Swift-XRT refined analysis
  93. GRB 081128: Liverpool Telescope afterglow confirmation
  94. GRB081128: optical observations
  95. GRB 081128: Enhanced Swift-XRT position
  96. GRB 081128: Optical observation of xinglong TNT
  97. GRB 081128: Swift detection of a burst
  98. GRB 081126: GRT Optical Observation
  99. GRB 081127: Swift/UVOT Upper Limits
  100. GRB 081127: Swift-XRT refined analysis

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