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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"

28072 results found.

  1. GRB 081109: GROND Detection of the Optical/NIR Afterglow Candidate
  2. GRB 081109A: Possible Swift-UVOT detection
  3. GRB 081109A: Faulkes Telescope South observations
  4. GRB 081109A: Swift-XRT refined analysis
  5. GRB 081109: Fermi GBM detection
  6. GRB 081109: Swift/UVOT upper limits
  7. GRB 081109A optical upper limit
  8. Swift-BAT Trigger 334129: possible burst
  9. GRB 081109: REM NIR afterglow detection
  10. GRB 081109: Swift detection of a burst
  11. GRB 081028 - PAIRITEL NIR detection
  12. GRB 081024C: Fermi Gamma-ray Burst Monitor detection
  13. SGR 1806-20: Fermi GBM detection
  14. GRB 081102B: Fermi GBM detection
  15. GRB 081105B: Fermi GBM detection
  16. GRB 081107: Fermi GBM detection
  17. GRB 081104: GROND found no Optical/NIR Afterglow
  18. GRB 081105: GROND Upper Limits
  19. GRB 081105: Observations from OSN
  20. UVOT/Swift observations of GRB081105
  21. Swift-XRT observations of GRB 081105
  22. GRB 081101B: Fermi GBM detection
  23. GRB 081025: Fermi GBM observation
  24. GRB 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
  25. GRB 081104: refined XRT analysis
  26. GRB 081104: Enhanced Swift-XRT position
  27. GRB081104: Swift/UVOT Upper Limits
  28. Fermi-GBM detection of a Solar Flare
  29. Fermi Detection of GRB 081102
  30. GRB 081104 : Faulkes Telescope South observations
  31. GRB 081104: Swift-XRT position
  32. GRB 081104: Swift detection of a burst
  33. GRB 081102: MASTER prompt optical limit
  34. GRB 081102: Swift-XRT refined analysis
  35. GRB 081102: Swift/UVOT refined analysis
  36. GRB 081102: Enhanced Swift-XRT position
  37. GRB 081102: OPTIMA-Burst optical upper limit
  38. GRB 081102: Swift detection of a burst
  39. GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
  40. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  41. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  42. GRB 081024B: BTA deep optical observations
  43. GRB 081028: CrAO optical observations
  44. GRB 081024B: new Swift-XRT observations
  45. Radio observation of GRB 080229b with ATCA
  46. GRB 081029, SMARTS optical/IR afterglow observations
  47. GRB 081029: UVOT Detection of the Optical Afterglow
  48. GRB 081029: PROMPT Detections
  49. GRB 081029: Redshift Confirmation from Gemini-South
  50. GRB081029: Swift XRT refined analysis
  51. GRB 081029: Enhanced Swift-XRT position
  52. GRB 081028: GROND Confirmation of the Optical/NIR Afterglow
  53. GRB 081029: REM observations
  54. GRB 081029: UVES/VLT Absorption Redshift
  55. GRB 081029: GROND Detection of the Optical/NIR Afterglow
  56. GRB 081029: ROTSE-III Detection of Optical Counterpart
  57. GRB 081029: Swift detection of a burst
  58. GRB 081028: Magellan redshift
  59. GRB 081028B: Fermi GBM detection
  60. GRB 081021: Fermi GBM detection
  61. GRB081028: UVOT detection of a brightening afterglow
  62. Swift UVOT observations of GRB081028
  63. GRB 081028: Swift-XRT refined analysis
  64. GRB 081028: Enhanced Swift-XRT position
  65. GRB 081028: optical observations at the NOT
  66. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  67. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  68. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  69. GRB 081028: Swift detection of a burst
  70. GRB 081025: TLS upper limits
  71. GRB 081024: No radio detection with the VLA
  72. GRB081025: RTT150 optical observations
  73. GRB081024B: P200 Observations
  74. GRB 081024B: Swift-XRT further observations
  75. GRB 081025 BAT refined analysis
  76. Swift UVOT observations of GRB081025
  77. GRB 081025: Swift-XRT position
  78. GRB 081024B: Swift-XRT observations
  79. GRB 081025: Burst detection from Swift-BAT slew data
  80. GRB 081024B: Fermi Gamma-ray Burst Monitor detection
  81. Swift UVOT observations of GRB 081024
  82. GRB 081024: Swift-XRT refined analysis
  83. GRB 081024, Swift-BAT refined analysis
  84. GRB 081024: Enhanced Swift-XRT position
  85. GRB 081024: Faulkes Telescope North optical observations
  86. GRB 081024: KAIT Optical Limits
  87. GRB 081024: Early Super-LOTIS Observations
  88. GRB 081024A: ROTSE-III Optical Limits
  89. GRB 081024: Swift detection of a burst
  90. GRB 081016A: Swift-XRT refined analysis
  91. GRB 081022: Swift detection of a burst
  92. GRB 081012: Swift-XRT Refined Analysis
  93. Swift detection of a possible burst (trigger 332287)
  94. GRB 081012 - Enhanced Swift XRT position
  95. GRB 081017: REM early observations
  96. GRB 081017: Swift detection of a burst
  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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