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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"

27327 results found.

  1. GRB 081223: Fermi GBM detection
  2. GRB 081221: GROND observations
  3. VLA radio upper limit on GRB 081222
  4. GRB 081222: Fermi GBM observation
  5. GRB 081221: Probable host galaxy in Keck imaging
  6. GRB 081204C: Fermi GBM detection
  7. GRB 081222, Swift-BAT refined analysis
  8. GRB 081221, Swift-BAT refined analysis
  9. GRB081222 optical limit by "Pi of the Sky"
  10. GRB 081222: Swift XRT refined analysis
  11. GRB081221: Fermi GBM observation
  12. IPN triangulation of bright GRB 081215A
  13. GRB 081222: Faulkes Telescope South observations
  14. GRB 081221: Gemini-N nIR imaging
  15. GRB081222, optical observation
  16. GRB081203A: BTA observation
  17. Konus-Wind observation of GRB 081221
  18. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  19. GRB081222: REM candidate afterglow
  20. GRB 081222: Swift detection of a burst with a bright optical afterglow
  21. GRB 081221: Enhanced Swift-XRT position
  22. GRB 081221: further NOT observations
  23. GRB 081221: NOT observations
  24. GRB 081221: Swift detection of a burst
  25. GRB 081217: Fermi GBM detection
  26. GRB 081211B: Further Swift-XRT analysis
  27. GRB 081215B: Fermi GBM detection
  28. GRB 081216: Suzaku WAM observation of the prompt emission
  29. GRB 081216 : Fermi GBM observation
  30. GRB 081215A: Fermi GBM detection
  31. GRB 081118: Zadko observations
  32. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  33. GRB 0811215A: MASTER prompt optical observations
  34. GRB 081215A: Andromeda inside Fermi error box: MASTER observations
  35. GRB 0811215A: Andromeda inside Fermi error box: MASTER observations
  36. Possible GRB 081211B: Swift/UVOT Upper Limits
  37. GRB 081213: Fermi GBM detection
  38. Possible GRB 081211B - Swift-XRT analysis
  39. GRB 081207: Fermi GBM detection
  40. GRB 081209: Fermi GBM detection
  41. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  42. GRB 081210, SMARTS optical/IR observations
  43. GRB 081211: Swift-BAT refined analysis
  44. GRB 081211: Swift XRT refined analysis
  45. GRB 081211: Enhanced Swift-XRT position
  46. GRB 081211: Swift detection of a burst
  47. GRB 081210: Swift-XRT refined analysis
  48. GRB081203B: optical observations
  49. GRB 081210: Enhanced Swift-XRT position
  50. GRB 081210: Swift-BAT refined analysis
  51. GRB 081210: Swift detection of a burst with optical afterglow
  52. IPN triangulation of short hard GRB 081209
  53. GRB 081203A: optical observations
  54. GRB 081206C: Fermi GBM detection
  55. Radio observation of GRB 081121 with ATCA
  56. Radio observation of GRB 081118 with ATCA
  57. GRB 081206B: Fermi GBM detection
  58. GRB 081206: Fermi GBM detection
  59. GRB 081128: afterglow observations
  60. GRB 081203B: Suzaku WAM observation of the prompt emission
  61. Radio observation of GRB 081109 with ATCA
  62. Radio observation of GRB 081104 with ATCA
  63. Radio observation of GRB 081029 with ATCA
  64. Radio observation of GRB 081008 with ATCA
  65. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  66. GRB081203A: Optical observations at Ishigaki
  67. GRB 081204: GROND Observations
  68. Radio detection of GRB 081203B with the VLA
  69. GRB081203A: Radio upper limit at 15 GHz
  70. GRB 081204B: Fermi GBM detection
  71. GRB 081204: Swift/UVOT Upper Limits
  72. GRB 081204: Swift XRT afterglow confirmation
  73. GRB081203A: MITSuME optical observation
  74. GRB081203A: optical observation
  75. GRB 081204 : a long GRB localized by INTEGRAL
  76. VLA Radio upper limit on GRB 081203A
  77. Swift-XRT observations of GRB 081203B
  78. GRB081203A: Swift-XRT refined analysis
  79. GRB 081203B: optical observations
  80. Swift/UVOT detection of GRB081203B
  81. GRB 081203B: Swift-XRT candidate afterglow.
  82. GRB 081203A: optical observations
  83. GRB081203A: Swift/UVOT grism redshift
  84. GRB 081203A: Burst detection from Swift-BAT slew data
  85. GRB 081203A: Swift-BAT refined analysis
  86. GRB 081203: Enhanced Swift-XRT position
  87. GRB 081130B: MASTER prompt optical observations
  88. GRB081203: optical observation
  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: afterglow photometry
  94. GRB 081126: Fermi GBM detection
  95. VLA Radio upper limit on GRB 081126
  96. GRB 081129: Fermi GBM detection
  97. GRB 081130: MASTER VWF prompt optical observations Fermi GRB
  98. GRB 081128A: optical observations
  99. Trigger 335971: Swift possible detection of a burst
  100. GRB081128: Swift/UVOT Upper Limits

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