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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 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-BAT refined analysis
  5. GRB 081109A: Swift-XRT refined analysis
  6. GRB 081109: Fermi GBM detection
  7. GRB 081109: Swift/UVOT upper limits
  8. GRB 081109A optical upper limit
  9. Swift-BAT Trigger 334129: possible burst
  10. GRB 081109: REM NIR afterglow detection
  11. GRB 081109: Swift detection of a burst
  12. GRB 081028 - PAIRITEL NIR detection
  13. GRB 081024C: Fermi Gamma-ray Burst Monitor detection
  14. SGR 1806-20: Fermi GBM detection
  15. GRB 081102B: Fermi GBM detection
  16. GRB 081105B: Fermi GBM detection
  17. GRB 081107: Fermi GBM detection
  18. GRB 081104: GROND found no Optical/NIR Afterglow
  19. GRB 081105: GROND Upper Limits
  20. Radio observation of GRB 080523 with ATCA
  21. Radio observation of GRB 080520 with ATCA
  22. GRB 081105: Observations from OSN
  23. UVOT/Swift observations of GRB081105
  24. Swift-XRT observations of GRB 081105
  25. GRB 081101B: Fermi GBM detection
  26. Radio observation of GRB 080516 with ATCA
  27. GRB 081105 Swift/BAT and IPN Localization
  28. GRB 081025: Fermi GBM observation
  29. GRB 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
  30. GRB 081104: refined XRT analysis
  31. GRB 081104: Enhanced Swift-XRT position
  32. GRB 081104: Swift-BAT refined analysis
  33. GRB081104: Swift/UVOT Upper Limits
  34. Fermi-GBM detection of a Solar Flare
  35. Fermi Detection of GRB 081102
  36. GRB 081104 : Faulkes Telescope South observations
  37. GRB 081104: Swift-XRT position
  38. GRB 081104: Swift detection of a burst
  39. Radio observation of GRB 080130 with ATCA
  40. GRB 081102: MASTER prompt optical limit
  41. GRB 081102: Swift-XRT refined analysis
  42. GRB 081102: Swift/UVOT refined analysis
  43. GRB 081102: Swift-BAT refined analysis
  44. GRB 081102: Enhanced Swift-XRT position
  45. Radio observation of GRB 080218b with ATCA
  46. Radio observation of GRB 080229a with ATCA
  47. GRB 081102: MASTER VWF promt observation
  48. GRB 081102: OPTIMA-Burst optical upper limit
  49. GRB 081102: Swift detection of a burst
  50. SGR 0501+4516: optical observations in August
  51. GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
  52. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  53. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  54. Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
  55. GRB 081024B: BTA deep optical observations
  56. GRB 081028: CrAO optical observations
  57. GRB 081024B: new Swift-XRT observations
  58. Radio observation of GRB 080229b with ATCA
  59. GRB 081029, SMARTS optical/IR afterglow observations
  60. GRB 081024B: VLA radio observation
  61. GRB 081029: UVOT Detection of the Optical Afterglow
  62. GRB 081029: PROMPT Detections
  63. GRB 081029: Redshift Confirmation from Gemini-South
  64. GRB 081029: Swift-BAT refined analysis
  65. GRB081029: Swift XRT refined analysis
  66. GRB 081025: Suzaku WAM observation of the prompt emission
  67. GRB 081024B: Suzaku WAM observation of the prompt emission
  68. GRB 081029: Enhanced Swift-XRT position
  69. GRB 081028: GROND Confirmation of the Optical/NIR Afterglow
  70. GRB 081029: REM observations
  71. Radio observation of GRB 080303 with ATCA
  72. Radio observation of GRB 080411 with ATCA
  73. GRB 081029: UVES/VLT Absorption Redshift
  74. GRB 081029: GROND Detection of the Optical/NIR Afterglow
  75. GRB 081029: ROTSE-III Detection of Optical Counterpart
  76. GRB 081029: Swift detection of a burst
  77. GRB 081028: Magellan redshift
  78. GRB 081028B: Fermi GBM detection
  79. GRB 081021: Fermi GBM detection
  80. GRB081028: UVOT detection of a brightening afterglow
  81. Swift UVOT observations of GRB081028
  82. GRB 081028: Swift-XRT refined analysis
  83. GRB 081028, Swift-BAT refined analysis
  84. GRB 081028: Enhanced Swift-XRT position
  85. GRB 081028: TAROT Calern observatory optical observations
  86. GRB 081028: optical observations at the NOT
  87. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  88. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  89. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  90. GRB 081028: Swift detection of a burst
  91. GRB 081025: TLS upper limits
  92. GRB 081024: No radio detection with the VLA
  93. GRB081025: RTT150 optical observations
  94. GRB081024B: P200 Observations
  95. GRB 081024B: Swift-XRT further observations
  96. GRB 081025 BAT refined analysis
  97. Swift UVOT observations of GRB081025
  98. Swift UVOT observations of GRB081024B
  99. Konus-Wind observation of GRB 081025
  100. GRB 081025: Swift-XRT position

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