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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"

26292 results found.

  1. GRB 090111: Swift-XRT refined analysis
  2. GRB 090111: Swift detection of a burst
  3. GRB 090107B: Suzaku WAM observation of the prompt emission
  4. GRB090107B: Fermi GBM Detection
  5. GRB 090107B: Swift XRT afterglow confirmation
  6. GRB 090107B: Swift/UVOT Observations
  7. GRB 090107B: Swift-XRT detection of possible afterglow
  8. GRB 090107B: ROTSE-III Optical Limits
  9. Fermi/GBM detection of GRB 081226A
  10. Fermi/GBM detection of GRB 081225
  11. GRB 090107: Swift-BAT refined analysis
  12. GRB 090107: Swift detection of a burst
  13. GRB 081231: Fermi GBM Detection
  14. GRB 090102: GRT Optical Observation
  15. Swift triggered on the HMXB 1A 1118-61
  16. Konus-Wind observation of GRB 090102
  17. GRB 081229: Fermi GBM detection
  18. Swift UVOT observations of GRB 090102
  19. GRB 090102: Swift-BAT refined analysis
  20. GRB 090102: Swift XRT refined analysis
  21. GRB 090102: TAROT Calern observatory optical light curve
  22. GRB 090102: Swift detection of a burst with an optical counterpart
  23. GRB 090102: TAROT Calern observatory optical observations
  24. GRB 081230: GROND confirmation of the afterglow
  25. GRB 081230, Swift-BAT refined analysis
  26. GRB 081230 Swift/UVOT Observations
  27. GRB 081230: Swift/UVOT Detection of an Optical Afterglow
  28. GRB 081230: ROTSE-III Detection of Optical Counterpart
  29. GRB 081230: Swift detection of a burst
  30. GRB 081228: GROND confirmation of the optical/NIR afterglow
  31. GRB 081226B: Fermi GBM observation
  32. GRB 081226C: Fermi GBM detection
  33. GRB 081228, Swift-BAT refined analysis
  34. GRB 081228: Swift/UVOT Upper Limits
  35. GRB 081228: Swift-XRT Team refined analysis
  36. GRB 081228: detection by GROND
  37. GRB 081228: TAROT Calern observatory optical observations
  38. GRB 081228: Swift detection of a burst
  39. GRB 081226B: Swift XRT and UVOT upper limits
  40. GRB 081224: Suzaku WAM observation of the prompt emission
  41. GRB 081226: Swift-XRT refined analysis
  42. GRB 081226A: Swift UVOT Upper Limits
  43. GRB 081226A: Swift-BAT refined analysis
  44. GRB 081226: ROTSE-III Optical Limits
  45. GRB 081226: Swift detection of a possible short-hard burst
  46. GRB 081224: Swift-XRT observation
  47. GRB 081224: Fermi GBM Detection & LAT Localization
  48. Konus-Wind observation of GRB 081222
  49. GRB 081223: Fermi GBM detection
  50. GRB 081221: GROND observations
  51. GRB 081222: Fermi GBM observation
  52. Fermi Gamma-ray Burst Monitor trigger 251687595 reclassification
  53. GRB081222: Swift/UVOT further observations
  54. GRB 081204C: Fermi GBM detection
  55. GRB 081222, Swift-BAT refined analysis
  56. GRB 081221, Swift-BAT refined analysis
  57. GRB081222 optical limit by "Pi of the Sky"
  58. Konus-Wind observation of very bright GRB 081215A
  59. GRB 081222: Swift XRT refined analysis
  60. GRB081221: Fermi GBM observation
  61. Swift/UVOT observations of GRB 081221
  62. IPN triangulation of bright GRB 081215A
  63. GRB 081221: Swift-XRT Refined Analysis
  64. GRB081222, optical observation
  65. GRB081222: Swift/UVOT detection of an optical afterglow
  66. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  67. GRB 081222: Swift detection of a burst with a bright optical afterglow
  68. GRB 081221: Swift detection of a burst
  69. GRB 081217: Fermi GBM detection
  70. Modification of Swift/UVOT response to bright GRBs
  71. GRB 081215B: Fermi GBM detection
  72. GRB 081216: Suzaku WAM observation of the prompt emission
  73. GRB 081216 : Fermi GBM observation
  74. GRB 081215A: Fermi GBM detection
  75. IPN localization of short hard GRB 081216
  76. GRB 081118: Zadko observations
  77. GRB 081213: Fermi GBM detection
  78. GRB 081207: Fermi GBM detection
  79. GRB 081209: Fermi GBM detection
  80. Fermi Gamma-ray Burst Monitor trigger 250533995 is not a GRB
  81. GRB 081211: Swift-BAT refined analysis
  82. GRB 081211: Swift XRT refined analysis
  83. GRB 081211: Swift/UVOT detection of an optical afterglow
  84. GRB 081210: Swift/UVOT refined analysis
  85. GRB 081211: Swift detection of a burst
  86. GRB 081210: Swift-XRT refined analysis
  87. GRB 081210: Swift-BAT refined analysis
  88. GRB 081210: Swift detection of a burst with optical afterglow
  89. Konus-Wind observation of GRB 081209
  90. IPN triangulation of short hard GRB 081209
  91. GRB 081206C: Fermi GBM detection
  92. GRB 081206B: Fermi GBM detection
  93. GRB 081206: Fermi GBM detection
  94. GRB 081203B: Suzaku WAM observation of the prompt emission
  95. GRB081203A: Optical observations at Ishigaki
  96. GRB 081204: GROND Observations
  97. GRB 081204B: Fermi GBM detection
  98. GRB 081204: Swift XRT afterglow confirmation
  99. GRB081203A: MITSuME optical observation
  100. GRB 081203A: Skynet/GORT Detections

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