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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"

28069 results found.

  1. GRB 081109A: Swift-XRT refined analysis
  2. GRB 081109: Fermi GBM detection
  3. GRB 081109: Swift/UVOT upper limits
  4. GRB 081109A optical upper limit
  5. Swift-BAT Trigger 334129: possible burst
  6. GRB 081109: REM NIR afterglow detection
  7. GRB 081109: Swift detection of a burst
  8. GRB 081028 - PAIRITEL NIR detection
  9. GRB 081024C: Fermi Gamma-ray Burst Monitor detection
  10. SGR 1806-20: Fermi GBM detection
  11. GRB 081102B: Fermi GBM detection
  12. GRB 081105B: Fermi GBM detection
  13. GRB 081107: Fermi GBM detection
  14. GRB 081104: GROND found no Optical/NIR Afterglow
  15. GRB 081105: GROND Upper Limits
  16. GRB 081105: Observations from OSN
  17. UVOT/Swift observations of GRB081105
  18. Swift-XRT observations of GRB 081105
  19. GRB 081101B: Fermi GBM detection
  20. GRB 081025: Fermi GBM observation
  21. GRB 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
  22. GRB 081104: refined XRT analysis
  23. GRB 081104: Enhanced Swift-XRT position
  24. GRB081104: Swift/UVOT Upper Limits
  25. Fermi-GBM detection of a Solar Flare
  26. Fermi Detection of GRB 081102
  27. GRB 081104 : Faulkes Telescope South observations
  28. GRB 081104: Swift-XRT position
  29. GRB 081104: Swift detection of a burst
  30. GRB 081102: MASTER prompt optical limit
  31. GRB 081102: Swift-XRT refined analysis
  32. GRB 081102: Swift/UVOT refined analysis
  33. GRB 081102: Enhanced Swift-XRT position
  34. GRB 081102: OPTIMA-Burst optical upper limit
  35. GRB 081102: Swift detection of a burst
  36. GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
  37. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  38. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  39. GRB 081024B: BTA deep optical observations
  40. GRB 081028: CrAO optical observations
  41. GRB 081024B: new Swift-XRT observations
  42. Radio observation of GRB 080229b with ATCA
  43. GRB 081029, SMARTS optical/IR afterglow observations
  44. GRB 081029: UVOT Detection of the Optical Afterglow
  45. GRB 081029: PROMPT Detections
  46. GRB 081029: Redshift Confirmation from Gemini-South
  47. GRB081029: Swift XRT refined analysis
  48. GRB 081029: Enhanced Swift-XRT position
  49. GRB 081028: GROND Confirmation of the Optical/NIR Afterglow
  50. GRB 081029: REM observations
  51. GRB 081029: UVES/VLT Absorption Redshift
  52. GRB 081029: GROND Detection of the Optical/NIR Afterglow
  53. GRB 081029: ROTSE-III Detection of Optical Counterpart
  54. GRB 081029: Swift detection of a burst
  55. GRB 081028: Magellan redshift
  56. GRB 081028B: Fermi GBM detection
  57. GRB 081021: Fermi GBM detection
  58. GRB081028: UVOT detection of a brightening afterglow
  59. Swift UVOT observations of GRB081028
  60. GRB 081028: Swift-XRT refined analysis
  61. GRB 081028: Enhanced Swift-XRT position
  62. GRB 081028: optical observations at the NOT
  63. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  64. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  65. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  66. GRB 081028: Swift detection of a burst
  67. GRB 081025: TLS upper limits
  68. GRB 081024: No radio detection with the VLA
  69. GRB081025: RTT150 optical observations
  70. GRB081024B: P200 Observations
  71. GRB 081024B: Swift-XRT further observations
  72. GRB 081025 BAT refined analysis
  73. Swift UVOT observations of GRB081025
  74. GRB 081025: Swift-XRT position
  75. GRB 081024B: Swift-XRT observations
  76. GRB 081025: Burst detection from Swift-BAT slew data
  77. GRB 081024B: Fermi Gamma-ray Burst Monitor detection
  78. Swift UVOT observations of GRB 081024
  79. GRB 081024: Swift-XRT refined analysis
  80. GRB 081024, Swift-BAT refined analysis
  81. GRB 081024: Enhanced Swift-XRT position
  82. GRB 081024: Faulkes Telescope North optical observations
  83. GRB 081024: KAIT Optical Limits
  84. GRB 081024: Early Super-LOTIS Observations
  85. GRB 081024A: ROTSE-III Optical Limits
  86. GRB 081024: Swift detection of a burst
  87. GRB 081016A: Swift-XRT refined analysis
  88. GRB 081022: Swift detection of a burst
  89. GRB 081012: Swift-XRT Refined Analysis
  90. Swift detection of a possible burst (trigger 332287)
  91. GRB 081012 - Enhanced Swift XRT position
  92. GRB 081017: REM early observations
  93. GRB 081017: Swift detection of a burst
  94. GRB 081016B: Swift/UVOT Upper Limits
  95. GRB 081011: Swift XRT refined analysis
  96. GRB 081016B: Swift-XRT Team refined Analysis
  97. GRB 081016B: Enhanced Swift-XRT position
  98. GRB 081016B: ROTSE-III Optical Limits
  99. GRB 081016B: Swift detection of a burst
  100. GRB 081011: Enhanced Swift-XRT position

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