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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 081102: Enhanced Swift-XRT position
  2. Radio observation of GRB 080218b with ATCA
  3. Radio observation of GRB 080229a with ATCA
  4. GRB 081102: MASTER VWF promt observation
  5. GRB 081102: OPTIMA-Burst optical upper limit
  6. GRB 081102: Swift detection of a burst
  7. SGR 0501+4516: optical observations in August
  8. GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
  9. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  10. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  11. Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
  12. GRB 081024B: BTA deep optical observations
  13. GRB 081028: CrAO optical observations
  14. GRB 081024B: new Swift-XRT observations
  15. Radio observation of GRB 080229b with ATCA
  16. GRB 081029, SMARTS optical/IR afterglow observations
  17. GRB 081024B: VLA radio observation
  18. GRB 081029: UVOT Detection of the Optical Afterglow
  19. GRB 081029: PROMPT Detections
  20. GRB 081029: Redshift Confirmation from Gemini-South
  21. GRB 081029: Swift-BAT refined analysis
  22. GRB081029: Swift XRT refined analysis
  23. GRB 081025: Suzaku WAM observation of the prompt emission
  24. GRB 081024B: Suzaku WAM observation of the prompt emission
  25. GRB 081029: Enhanced Swift-XRT position
  26. GRB 081028: GROND Confirmation of the Optical/NIR Afterglow
  27. GRB 081029: REM observations
  28. Radio observation of GRB 080303 with ATCA
  29. Radio observation of GRB 080411 with ATCA
  30. GRB 081029: UVES/VLT Absorption Redshift
  31. GRB 081029: GROND Detection of the Optical/NIR Afterglow
  32. GRB 081029: ROTSE-III Detection of Optical Counterpart
  33. GRB 081029: Swift detection of a burst
  34. GRB 081028: Magellan redshift
  35. GRB 081028B: Fermi GBM detection
  36. GRB 081021: Fermi GBM detection
  37. GRB081028: UVOT detection of a brightening afterglow
  38. Swift UVOT observations of GRB081028
  39. GRB 081028: Swift-XRT refined analysis
  40. GRB 081028, Swift-BAT refined analysis
  41. GRB 081028: Enhanced Swift-XRT position
  42. GRB 081028: TAROT Calern observatory optical observations
  43. GRB 081028: optical observations at the NOT
  44. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  45. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  46. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  47. GRB 081028: Swift detection of a burst
  48. GRB 081025: TLS upper limits
  49. GRB 081024: No radio detection with the VLA
  50. GRB081025: RTT150 optical observations
  51. GRB081024B: P200 Observations
  52. GRB 081024B: Swift-XRT further observations
  53. GRB 081025 BAT refined analysis
  54. Swift UVOT observations of GRB081025
  55. Swift UVOT observations of GRB081024B
  56. Konus-Wind observation of GRB 081025
  57. GRB 081025: Swift-XRT position
  58. GRB 081024B: Swift-XRT observations
  59. GRB 081025: Burst detection from Swift-BAT slew data
  60. GRB 081024B: Fermi Gamma-ray Burst Monitor detection
  61. Fermi-LAT observation of GRB 081024B
  62. Swift UVOT observations of GRB 081024
  63. GRB 081024: Swift-XRT refined analysis
  64. GRB 081024, Swift-BAT refined analysis
  65. GRB 081024: Enhanced Swift-XRT position
  66. GRB 081024: Faulkes Telescope North optical observations
  67. GRB 081024: KAIT Optical Limits
  68. GRB 081024: Early Super-LOTIS Observations
  69. GRB 081024A: ROTSE-III Optical Limits
  70. GRB 081024: Swift detection of a burst
  71. GRB 081022, Swift-BAT refined analysis
  72. GRB 081016A: Swift-XRT refined analysis
  73. GRB 081022: Swift detection of a burst
  74. GRB 081012: Swift-XRT Refined Analysis
  75. Swift trigger 332287 is not a GRB
  76. Swift detection of a possible burst (trigger 332287)
  77. GRB 081012 - Enhanced Swift XRT position
  78. GRB 081017, Swift-BAT refined analysis
  79. GRB 081017: REM early observations
  80. GRB 081017: Swift detection of a burst
  81. GRB 081016B, Swift-BAT refined analysis
  82. GRB 081016B: Swift/UVOT Upper Limits
  83. GRB 081011: Swift XRT refined analysis
  84. GRB 081016B: Swift-XRT Team refined Analysis
  85. GRB 081016B: Enhanced Swift-XRT position
  86. GRB 081016B: ROTSE-III Optical Limits
  87. GRB 081016B: Swift detection of a burst
  88. GRB 081011: Enhanced Swift-XRT position
  89. GRB 081016: Swift-XRT candidate afterglow detection
  90. Swift detection of flare on CC Eri
  91. GRB 081016: A long GRB discovered by INTEGRAL
  92. Trigger 331721 Due to Swift startracker loss-of-lock
  93. Detection of flare star Algol in Swift-BAT slew data
  94. GRB 081009: Fermi GBM detection
  95. GRB 081012: GROND upper limits
  96. GRB 081008: Galaxy associated with z=1.967 absorber
  97. Swift-BAT triggered on the flare star Algol
  98. GRB 081012: Fermi GBM detection
  99. GRB 081007 and GRB 081007B: Fermi GBM detection
  100. GRB 080430: optical observations

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