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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"
  1. GRB 090422: Swift-BAT refined analysis
  2. GRB 090422: Enhanced Swift-XRT position
  3. GRB 090410: Erratum in GCN 9189
  4. GRB 090408A: Erratum in GCN 9188
  5. GRB 090418B: RTT150 optical observations
  6. GRB 090418A: RTT150 optical observations
  7. GRB 080410: GAO 150cm telescope Optical Observation
  8. GRB 080408A: GAO 150cm telescope Optical Observation
  9. GRB 090422: Liverpool Telescope observations
  10. GRB 090418B: Suzaku WAM observation of the prompt emission
  11. GRB 090422: Swift detection of a burst
  12. GRB 090418C: Fermi GBM Detection
  13. GRB 090418A: Swift/UVOT Detection of the Neighbouring Galaxy
  14. Swift-BAT trigger 349718 is not a burst
  15. GRB 090418B: GRAS002 observatios
  16. GRB 090417B: Optical observation
  17. GRB 090418A: optical observations
  18. GRB 090418B: GROND observations
  19. GRB 090419: Swift/UVOT Observations
  20. GRB 090418B: Faulkes Telescope North observations
  21. GRB 090418A: Swift/UVOT Observations
  22. GRB 090417B: Swift/UVOT Upper Limits
  23. GRB 090417B Correction to the BAT refined analysis position
  24. GRB 090419: Swift-XRT refined analysis
  25. Konus-Wind observation of GRB 090418B
  26. GRB 090418: Erratum in GCN 9168
  27. GRB 090419: GROND detection of afterglow candidate
  28. GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
  29. GRB 090419: Swift-BAT refined analysis
  30. VLA radio detection of GRB 090418
  31. VLA radio upper limit on GRB 090417B
  32. GRB 090419: Enhanced Swift-XRT position
  33. GRB 090418: Swift XRT refined analysis
  34. GRB 090418A: ROTSE-III Refined Analysis
  35. GRB 090419: Swift detection of a burst
  36. VLA observations of short burst GRB 090417A
  37. GRB 090418B: Detection of a bright burst from Swift-BAT slew data
  38. GRB 090417B: Gemini imaging
  39. GRB 090418: Swift-BAT refined analysis
  40. GRB 090417B: Galaxy redshift
  41. GRB 090417B: Swift-XRT refined analysis
  42. GRB 090418: Enhanced Swift-XRT position
  43. GRB 090417B: Swift-BAT further refined analysis
  44. GRB 090418: PAIRITEL NIR detection
  45. GRB 090418 Lick Redshift
  46. GRB 090418: ROTSE-III Confirmation of Optical Counterpart
  47. GRB 090418: Swift detection of a burst with optical afterglow
  48. GRB 090418 OA candidate
  49. GRB 090411B: Suzaku WAM observation of the prompt emission
  50. GRB 090411A: Suzaku WAM observation of the prompt emission
  51. GRB 090417B: Subaru NIR Observations
  52. GRB 090417B: Liverpool Telescope observations
  53. GRB 090417B: MITSuME Okayama optical upper limits
  54. GRB090417B: Xinglong TNT optical upper limit
  55. GRB 090417B: optical observations
  56. GRB090417B: optical observations
  57. GRB 090417B: Swift-BAT refined analysis
  58. GRB 090417A: Swift-BAT refined analysis
  59. GRB 090417A: Early-type nature of the putative host
  60. GRB 090417A: nearby galaxy redshift
  61. GRB 090417B: Swift detection of a burst
  62. GRB 090417: 2MASS galaxy within BAT Localization
  63. GRB 090417: Swift detection of a short burst
  64. GRB 090412: Fermi GBM detection
  65. GRB 090411B: Fermi GBM detection
  66. GRB 090411A: Fermi GBM detection
  67. GRB 090410: Suzaku WAM observation of the prompt emission
  68. GRB 090410: GROND upper limits
  69. Fermi GBM trigger 261106787 is not a GRB
  70. GRB 090410: MITSuME optical upper limits
  71. GRB 090408b: IPN Triangulation
  72. GRB 090328b: IPN Triangulation
  73. GRB 090410: Swift-BAT refined analysis
  74. GRB 090410: Swift detection of a burst
  75. Konus-Wind and Konus-RF observations of GRB 090408b
  76. GRB090408 : TAOS optical observations
  77. GRB 090409: Fermi GBM detection
  78. Swift-BAT Trigger 348781 is not a GRB
  79. Swift-BAT Trigger 348720 is not a GRB
  80. GRB 090406: pseudo-z= 0.91 from prompt emission spectrum
  81. GRB090408, RIMOTS optical upper limits
  82. GRB 090408: Xinglong TNT optical Upper Limit
  83. Swift-BAT trigger 348781: almost certainly not a burst
  84. Fermi GBM Detection of a weak source
  85. GRB 090408B: MASTER II-Kourovka optical observations
  86. GRB 090408: Swift detection of a burst
  87. GRB 090407: GROND upper limits
  88. GRB 090407: VLT observations
  89. GRB 090407: Swift-XRT refined analysis
  90. GRB 090407: Swift UVOT Upper Limits
  91. GRB 090407: Enhanced Swift-XRT position
  92. GRB 090407: Swift-BAT refined analysis
  93. Konus-Wind and Konus-RF observations of GRB 090406
  94. GRB 090407: ROTSE-III Optical Limits
  95. GRB 090407: Swift detection of a burst
  96. GRB 090404: millimeter detection
  97. GRB 090404: nIR observations at Calar Alto
  98. GRB 090405: Fermi GBM Detection
  99. GRB 090403: Fermi GBM detection
  100. GRB 090404: GROND upper limits

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