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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 081126: Enhanced Swift-XRT position
  2. GRB 081126: TAROT Calern observatory optical observations
  3. GRB 081126: Swift detection of a burst
  4. GRB 081125: Fermi GBM detection
  5. GRB 081124: Fermi GBM detection
  6. GRB 081120: Fermi GBM detection
  7. GRB 081118: Fermi GBM detection.
  8. GRB 081122: Fermi GBM detection
  9. Konus-Wind observation of GRB 081121
  10. GRB 081121, SMARTS optical/IR afterglow observations
  11. GRB081121: Fermi GBM detection
  12. Fermi GBM detection of a weak source
  13. GRB081121: Refined Swift/UVOT observations
  14. GRB 081121: Swift-XRT refined analysis
  15. GRB 081121: Magellan Redshift
  16. GRB 081121: Enhanced Swift-XRT position
  17. GRB 081121: GROND observations
  18. GRB 081121: Swift-BAT refined analysis
  19. GRB081121: Swift/UVOT observations
  20. GRB 081121: Swift detection of a burst
  21. GRB 081121: ROTSE-III Detection of Optical Counterpart
  22. GRB081118 : optical upper limit
  23. GRB 081016b, SMARTS optical/IR observations
  24. GRB 081119: Fermi GBM detection
  25. VLA Radio upper limit on GRB 081118
  26. GRB 081118: VLT redshift
  27. GRB 081118: Swift-XRT refined analysis
  28. GRB 081118: GROND detection of afterglow
  29. GRB 081118: optical afterglow candidate
  30. GRB 081118: Swift UVOT Upper Limits
  31. GRB 081118: Swift-BAT refined analysis
  32. GRB 081118: Enhanced Swift-XRT position
  33. GRB 081118: Swift detection of a burst
  34. GRB 081109A: confirmation of possible detection host galaxy
  35. Further Swift-XRT observations of the probable GRB 081105.
  36. GRB 081113: Fermi GBM detection
  37. GRB 081102: RTT150 Optical observations
  38. GRB 081110: Fermi GBM detection
  39. GRB 081110: MASTER: first optical observations Fermi GRB
  40. GRB 081109: TAROT La Silla observatory optical observations
  41. GRB 081102: MASTER refind and final results
  42. GRB 081109: GROND redshift limit and host extinction
  43. GRB 081025: Swift-XRT further analysis
  44. GRB 081024B: Swift-XRT late-time observations
  45. Swift-BAT refined analysis of trigger 334129
  46. GRB 081109B: Swift/UVOT refined analysis
  47. GRB 081109: GROND Detection of the Optical/NIR Afterglow Candidate
  48. GRB 081109A: Possible Swift-UVOT detection
  49. GRB 081109A: Faulkes Telescope South observations
  50. GRB 081109A, Swift-BAT refined analysis
  51. GRB 081109A: Swift-XRT refined analysis
  52. GRB 081109: Fermi GBM detection
  53. GRB 081109: Swift/UVOT upper limits
  54. GRB 081109A optical upper limit
  55. Swift-BAT Trigger 334129: possible burst
  56. GRB 081109: REM NIR afterglow detection
  57. GRB 081109: Swift detection of a burst
  58. GRB 081028 - PAIRITEL NIR detection
  59. GRB 081024C: Fermi Gamma-ray Burst Monitor detection
  60. SGR 1806-20: Fermi GBM detection
  61. GRB 081102B: Fermi GBM detection
  62. GRB 081105B: Fermi GBM detection
  63. GRB 081107: Fermi GBM detection
  64. GRB 081104: GROND found no Optical/NIR Afterglow
  65. GRB 081105: GROND Upper Limits
  66. Radio observation of GRB 080523 with ATCA
  67. Radio observation of GRB 080520 with ATCA
  68. GRB 081105: Observations from OSN
  69. UVOT/Swift observations of GRB081105
  70. Swift-XRT observations of GRB 081105
  71. GRB 081101B: Fermi GBM detection
  72. Radio observation of GRB 080516 with ATCA
  73. GRB 081105 Swift/BAT and IPN Localization
  74. GRB 081025: Fermi GBM observation
  75. GRB 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
  76. GRB 081104: refined XRT analysis
  77. GRB 081104: Enhanced Swift-XRT position
  78. GRB 081104: Swift-BAT refined analysis
  79. GRB081104: Swift/UVOT Upper Limits
  80. Fermi-GBM detection of a Solar Flare
  81. Fermi Detection of GRB 081102
  82. GRB 081104 : Faulkes Telescope South observations
  83. GRB 081104: Swift-XRT position
  84. GRB 081104: Swift detection of a burst
  85. Radio observation of GRB 080130 with ATCA
  86. GRB 081102: MASTER prompt optical limit
  87. GRB 081102: Swift-XRT refined analysis
  88. GRB 081102: Swift/UVOT refined analysis
  89. GRB 081102: Swift-BAT refined analysis
  90. GRB 081102: Enhanced Swift-XRT position
  91. Radio observation of GRB 080218b with ATCA
  92. Radio observation of GRB 080229a with ATCA
  93. GRB 081102: MASTER VWF promt observation
  94. GRB 081102: OPTIMA-Burst optical upper limit
  95. GRB 081102: Swift detection of a burst
  96. SGR 0501+4516: optical observations in August
  97. GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
  98. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  99. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  100. Swift-BAT triggered on a probable GRB 081101 (trigger=333320)

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