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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"

20351 results found.

  1. GRB 081228: detection by GROND
  2. GRB 081228: Enhanced Swift-XRT position
  3. GRB 081228: TAROT Calern observatory optical observations
  4. GRB 081228: Swift detection of a burst
  5. VLA radio observation of GRB 081221
  6. GRB 081226B: Swift XRT and UVOT upper limits
  7. GRB 081226: Swift-XRT refined analysis
  8. GRB 081226A: Swift UVOT Upper Limits
  9. GRB 081226: GROND afterglow candidate
  10. GRB 081226: ROTSE-III Optical Limits
  11. GRB 081226: Swift detection of a possible short-hard burst
  12. GRB 080810: optical observations
  13. GRB 081211B: optical observations
  14. GRB 081224: Swift-XRT observation
  15. GRB 081222: MITSuME optical observation
  16. GRB 081221: GROND observations
  17. VLA radio upper limit on GRB 081222
  18. GRB 081221: Probable host galaxy in Keck imaging
  19. GRB 081222, Swift-BAT refined analysis
  20. GRB081222 optical limit by "Pi of the Sky"
  21. Konus-Wind observation of very bright GRB 081215A
  22. GRB 081222: Swift XRT refined analysis
  23. IPN triangulation of bright GRB 081215A
  24. GRB 081222: Faulkes Telescope South observations
  25. GRB 081221: Gemini-N nIR imaging
  26. GRB081222, optical observation
  27. GRB081203A: BTA observation
  28. Konus-Wind observation of GRB 081221
  29. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  30. GRB081222: REM candidate afterglow
  31. GRB 081222: Swift detection of a burst with a bright optical afterglow
  32. GRB 081221: Enhanced Swift-XRT position
  33. GRB 081221: further NOT observations
  34. GRB 081221: NOT observations
  35. GRB 081221: Swift detection of a burst
  36. GRB 081118: Zadko observations
  37. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  38. GRB 0811215A: MASTER prompt optical observations
  39. GRB 081215A: Andromeda inside Fermi error box: MASTER observations
  40. GRB 0811215A: Andromeda inside Fermi error box: MASTER observations
  41. Possible GRB 081211B: Swift/UVOT Upper Limits
  42. Possible GRB 081211B - Swift-XRT analysis
  43. GRB 081207: Fermi GBM detection
  44. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  45. GRB 081210, SMARTS optical/IR observations
  46. GRB 081211: Enhanced Swift-XRT position
  47. GRB 081211: Swift detection of a burst
  48. GRB081203B: optical observations
  49. GRB 081210: Enhanced Swift-XRT position
  50. GRB 081210: Swift detection of a burst with optical afterglow
  51. IPN triangulation of short hard GRB 081209
  52. GRB 081203A: optical observations
  53. GRB 081128: afterglow observations
  54. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  55. GRB 081128: optical observation in CrAO
  56. GRB081203A: Optical observations at Ishigaki
  57. GRB 081204: GROND Observations
  58. Radio detection of GRB 081203B with the VLA
  59. GRB081203A: Radio upper limit at 15 GHz
  60. GRB 081204B: Fermi GBM detection
  61. GRB 081204: Swift/UVOT Upper Limits
  62. GRB 081204: Swift XRT afterglow confirmation
  63. GRB081203A: MITSuME optical observation
  64. GRB081203A: optical observation
  65. VLA Radio upper limit on GRB 081203A
  66. GRB 081203B: optical observations
  67. Swift/UVOT detection of GRB081203B
  68. GRB 081203B: Swift-XRT candidate afterglow.
  69. GRB 081203A: optical observations
  70. GRB 081203: Enhanced Swift-XRT position
  71. GRB 081130B: MASTER prompt optical observations
  72. GRB081203: optical observation
  73. GRB 081203: Swift detection of a burst with a bright optical counterpart
  74. Swift Trigger 335971: Swift/UVOT Observations
  75. GRB 081126: afterglow photometry
  76. VLA Radio upper limit on GRB 081126
  77. GRB 081130: MASTER VWF prompt optical observations Fermi GRB
  78. GRB 081128A: optical observations
  79. Trigger 335971: Swift possible detection of a burst
  80. GRB081128: Swift/UVOT Upper Limits
  81. GRB 081128: Swift-XRT refined analysis
  82. GRB 081128: Liverpool Telescope afterglow confirmation
  83. GRB081128: optical observations
  84. GRB 081128: Enhanced Swift-XRT position
  85. GRB 081128: Optical observation of xinglong TNT
  86. GRB 081128: Swift detection of a burst
  87. GRB 081126: GRT Optical Observation
  88. GRB 081127: Swift/UVOT Upper Limits
  89. GRB 081127: Swift-XRT refined analysis
  90. GRB 081127: Enhanced Swift-XRT position
  91. GRB 081127: Swift detection of a burst
  92. GRB 081126: Swift/UVOT Observations
  93. GRB 081126: optical observations
  94. GRB 081126: Swift-BAT refined analysis
  95. GRB 081126: Enhanced Swift-XRT position
  96. GRB 081126: TAROT Calern observatory optical observations
  97. GRB 081126: Swift detection of a burst
  98. GRB 081121, SMARTS optical/IR afterglow observations
  99. GRB081121: Fermi GBM detection
  100. GRB081121: Refined Swift/UVOT observations

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