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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 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
  2. GRB 081104: refined XRT analysis
  3. GRB 081104: Enhanced Swift-XRT position
  4. GRB 081104: Swift-BAT refined analysis
  5. GRB081104: Swift/UVOT Upper Limits
  6. Fermi-GBM detection of a Solar Flare
  7. Fermi Detection of GRB 081102
  8. GRB 081104 : Faulkes Telescope South observations
  9. GRB 081104: Swift-XRT position
  10. GRB 081104: Swift detection of a burst
  11. Radio observation of GRB 080130 with ATCA
  12. GRB 081102: MASTER prompt optical limit
  13. GRB 081102: Swift-XRT refined analysis
  14. GRB 081102: Swift/UVOT refined analysis
  15. GRB 081102: Swift-BAT refined analysis
  16. GRB 081102: Enhanced Swift-XRT position
  17. Radio observation of GRB 080218b with ATCA
  18. Radio observation of GRB 080229a with ATCA
  19. GRB 081102: MASTER VWF promt observation
  20. GRB 081102: OPTIMA-Burst optical upper limit
  21. GRB 081102: Swift detection of a burst
  22. SGR 0501+4516: optical observations in August
  23. GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
  24. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  25. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  26. Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
  27. GRB 081024B: BTA deep optical observations
  28. GRB 081028: CrAO optical observations
  29. GRB 081024B: new Swift-XRT observations
  30. Radio observation of GRB 080229b with ATCA
  31. GRB 081029, SMARTS optical/IR afterglow observations
  32. GRB 081024B: VLA radio observation
  33. GRB 081029: UVOT Detection of the Optical Afterglow
  34. GRB 081029: PROMPT Detections
  35. GRB 081029: Redshift Confirmation from Gemini-South
  36. GRB 081029: Swift-BAT refined analysis
  37. GRB081029: Swift XRT refined analysis
  38. GRB 081025: Suzaku WAM observation of the prompt emission
  39. GRB 081024B: Suzaku WAM observation of the prompt emission
  40. GRB 081029: Enhanced Swift-XRT position
  41. GRB 081028: GROND Confirmation of the Optical/NIR Afterglow
  42. GRB 081029: REM observations
  43. Radio observation of GRB 080303 with ATCA
  44. Radio observation of GRB 080411 with ATCA
  45. GRB 081029: UVES/VLT Absorption Redshift
  46. GRB 081029: GROND Detection of the Optical/NIR Afterglow
  47. GRB 081029: ROTSE-III Detection of Optical Counterpart
  48. GRB 081029: Swift detection of a burst
  49. GRB 081028: Magellan redshift
  50. GRB 081028B: Fermi GBM detection
  51. GRB 081021: Fermi GBM detection
  52. GRB081028: UVOT detection of a brightening afterglow
  53. Swift UVOT observations of GRB081028
  54. GRB 081028: Swift-XRT refined analysis
  55. GRB 081028, Swift-BAT refined analysis
  56. GRB 081028: Enhanced Swift-XRT position
  57. GRB 081028: TAROT Calern observatory optical observations
  58. GRB 081028: optical observations at the NOT
  59. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  60. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  61. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  62. GRB 081028: Swift detection of a burst
  63. GRB 081025: TLS upper limits
  64. GRB 081024: No radio detection with the VLA
  65. GRB081025: RTT150 optical observations
  66. GRB081024B: P200 Observations
  67. GRB 081024B: Swift-XRT further observations
  68. GRB 081025 BAT refined analysis
  69. Swift UVOT observations of GRB081025
  70. Swift UVOT observations of GRB081024B
  71. Konus-Wind observation of GRB 081025
  72. GRB 081025: Swift-XRT position
  73. GRB 081024B: Swift-XRT observations
  74. GRB 081025: Burst detection from Swift-BAT slew data
  75. GRB 081024B: Fermi Gamma-ray Burst Monitor detection
  76. Fermi-LAT observation of GRB 081024B
  77. Swift UVOT observations of GRB 081024
  78. GRB 081024: Swift-XRT refined analysis
  79. GRB 081024, Swift-BAT refined analysis
  80. GRB 081024: Enhanced Swift-XRT position
  81. GRB 081024: Faulkes Telescope North optical observations
  82. GRB 081024: KAIT Optical Limits
  83. GRB 081024: Early Super-LOTIS Observations
  84. GRB 081024A: ROTSE-III Optical Limits
  85. GRB 081024: Swift detection of a burst
  86. GRB 081022, Swift-BAT refined analysis
  87. GRB 081016A: Swift-XRT refined analysis
  88. GRB 081022: Swift detection of a burst
  89. GRB 081012: Swift-XRT Refined Analysis
  90. Swift trigger 332287 is not a GRB
  91. Swift detection of a possible burst (trigger 332287)
  92. GRB 081012 - Enhanced Swift XRT position
  93. GRB 081017, Swift-BAT refined analysis
  94. GRB 081017: REM early observations
  95. GRB 081017: Swift detection of a burst
  96. GRB 081016B, Swift-BAT refined analysis
  97. GRB 081016B: Swift/UVOT Upper Limits
  98. GRB 081011: Swift XRT refined analysis
  99. GRB 081016B: Swift-XRT Team refined Analysis
  100. GRB 081016B: Enhanced Swift-XRT position

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