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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"

27394 results found.

  1. GRB 081121: Swift-BAT refined analysis
  2. GRB081121: Swift/UVOT observations
  3. GRB 081121: ROTSE-III Detection of Optical Counterpart
  4. GRB081118 : optical upper limit
  5. GRB 081119: Fermi GBM detection
  6. VLA Radio upper limit on GRB 081118
  7. GRB 081118: Swift-XRT refined analysis
  8. GRB 081118: GROND detection of afterglow
  9. GRB 081118: optical afterglow candidate
  10. GRB 081118: Swift UVOT Upper Limits
  11. GRB 081118: Swift-BAT refined analysis
  12. GRB 081118: Enhanced Swift-XRT position
  13. GRB 081118: Swift detection of a burst
  14. GRB 081109A: confirmation of possible detection host galaxy
  15. Further Swift-XRT observations of the probable GRB 081105.
  16. GRB 081113: Fermi GBM detection
  17. GRB 081102: RTT150 Optical observations
  18. GRB 081110: Fermi GBM detection
  19. GRB 081109: TAROT La Silla observatory optical observations
  20. GRB 081102: MASTER refind and final results
  21. GRB 081109: GROND redshift limit and host extinction
  22. GRB 081025: Swift-XRT further analysis
  23. GRB 081024B: Swift-XRT late-time observations
  24. GRB 081109: GROND Detection of the Optical/NIR Afterglow Candidate
  25. GRB 081109A, Swift-BAT refined analysis
  26. GRB 081109A: Swift-XRT refined analysis
  27. GRB 081109: Fermi GBM detection
  28. Swift-BAT Trigger 334129: possible burst
  29. GRB 081109: REM NIR afterglow detection
  30. GRB 081109: Swift detection of a burst
  31. GRB 081024C: Fermi Gamma-ray Burst Monitor detection
  32. SGR 1806-20: Fermi GBM detection
  33. GRB 081102B: Fermi GBM detection
  34. GRB 081105B: Fermi GBM detection
  35. GRB 081107: Fermi GBM detection
  36. GRB 081104: GROND found no Optical/NIR Afterglow
  37. GRB 081105: GROND Upper Limits
  38. Radio observation of GRB 080523 with ATCA
  39. Radio observation of GRB 080520 with ATCA
  40. GRB 081105: Observations from OSN
  41. Swift-XRT observations of GRB 081105
  42. GRB 081101B: Fermi GBM detection
  43. Radio observation of GRB 080516 with ATCA
  44. GRB 081105 Swift/BAT and IPN Localization
  45. GRB 081025: Fermi GBM observation
  46. GRB 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
  47. GRB 081104: refined XRT analysis
  48. GRB 081104: Enhanced Swift-XRT position
  49. GRB 081104: Swift-BAT refined analysis
  50. GRB 081104 : Faulkes Telescope South observations
  51. Radio observation of GRB 080130 with ATCA
  52. GRB 081102: MASTER prompt optical limit
  53. GRB 081102: Swift-XRT refined analysis
  54. GRB 081102: Swift-BAT refined analysis
  55. GRB 081102: Enhanced Swift-XRT position
  56. Radio observation of GRB 080218b with ATCA
  57. Radio observation of GRB 080229a with ATCA
  58. GRB 081102: MASTER VWF promt observation
  59. GRB 081102: Swift detection of a burst
  60. SGR 0501+4516: optical observations in August
  61. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  62. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  63. GRB 081024B: BTA deep optical observations
  64. GRB 081024B: new Swift-XRT observations
  65. Radio observation of GRB 080229b with ATCA
  66. GRB 081024B: VLA radio observation
  67. GRB 081029: UVOT Detection of the Optical Afterglow
  68. GRB 081029: Swift-BAT refined analysis
  69. GRB081029: Swift XRT refined analysis
  70. GRB 081025: Suzaku WAM observation of the prompt emission
  71. GRB 081029: Enhanced Swift-XRT position
  72. GRB 081028: GROND Confirmation of the Optical/NIR Afterglow
  73. GRB 081029: REM observations
  74. Radio observation of GRB 080303 with ATCA
  75. Radio observation of GRB 080411 with ATCA
  76. GRB 081029: GROND Detection of the Optical/NIR Afterglow
  77. GRB 081029: ROTSE-III Detection of Optical Counterpart
  78. GRB 081028B: Fermi GBM detection
  79. GRB 081021: Fermi GBM detection
  80. Swift UVOT observations of GRB081028
  81. GRB 081028: Swift-XRT refined analysis
  82. GRB 081028, Swift-BAT refined analysis
  83. GRB 081028: Enhanced Swift-XRT position
  84. GRB 081028: TAROT Calern observatory optical observations
  85. GRB 081028: optical observations at the NOT
  86. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  87. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  88. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  89. GRB 081028: Swift detection of a burst
  90. GRB 081024: No radio detection with the VLA
  91. GRB081025: RTT150 optical observations
  92. GRB081024B: P200 Observations
  93. GRB 081024B: Swift-XRT further observations
  94. GRB 081025 BAT refined analysis
  95. Swift UVOT observations of GRB081024B
  96. Konus-Wind observation of GRB 081025
  97. GRB 081025: Swift-XRT position
  98. GRB 081024B: Swift-XRT observations
  99. GRB 081025: Burst detection from Swift-BAT slew data
  100. GRB 081024: Swift-XRT refined analysis

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