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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"

27405 results found.

  1. GRB 081125: Fermi GBM detection
  2. GRB 081124: Fermi GBM detection
  3. GRB 081120: Fermi GBM detection
  4. GRB 081118: Fermi GBM detection.
  5. GRB 081122: Fermi GBM detection
  6. GRB 081121, SMARTS optical/IR afterglow observations
  7. Fermi GBM detection of a weak source
  8. GRB081121: Refined Swift/UVOT observations
  9. GRB 081121: Swift-XRT refined analysis
  10. GRB 081121: Enhanced Swift-XRT position
  11. GRB 081121: GROND observations
  12. GRB 081121: Swift-BAT refined analysis
  13. GRB081121: Swift/UVOT observations
  14. GRB 081121: ROTSE-III Detection of Optical Counterpart
  15. GRB081118 : optical upper limit
  16. GRB 081119: Fermi GBM detection
  17. VLA Radio upper limit on GRB 081118
  18. GRB 081118: Swift-XRT refined analysis
  19. GRB 081118: GROND detection of afterglow
  20. GRB 081118: optical afterglow candidate
  21. GRB 081118: Swift UVOT Upper Limits
  22. GRB 081118: Swift-BAT refined analysis
  23. GRB 081118: Enhanced Swift-XRT position
  24. GRB 081118: Swift detection of a burst
  25. GRB 081109A: confirmation of possible detection host galaxy
  26. Further Swift-XRT observations of the probable GRB 081105.
  27. GRB 081113: Fermi GBM detection
  28. GRB 081102: RTT150 Optical observations
  29. GRB 081110: Fermi GBM detection
  30. GRB 081109: TAROT La Silla observatory optical observations
  31. GRB 081102: MASTER refind and final results
  32. GRB 081109: GROND redshift limit and host extinction
  33. GRB 081025: Swift-XRT further analysis
  34. GRB 081024B: Swift-XRT late-time observations
  35. GRB 081109: GROND Detection of the Optical/NIR Afterglow Candidate
  36. GRB 081109A, Swift-BAT refined analysis
  37. GRB 081109A: Swift-XRT refined analysis
  38. GRB 081109: Fermi GBM detection
  39. Swift-BAT Trigger 334129: possible burst
  40. GRB 081109: REM NIR afterglow detection
  41. GRB 081109: Swift detection of a burst
  42. GRB 081024C: Fermi Gamma-ray Burst Monitor detection
  43. SGR 1806-20: Fermi GBM detection
  44. GRB 081102B: Fermi GBM detection
  45. GRB 081105B: Fermi GBM detection
  46. GRB 081107: Fermi GBM detection
  47. GRB 081104: GROND found no Optical/NIR Afterglow
  48. GRB 081105: GROND Upper Limits
  49. Radio observation of GRB 080523 with ATCA
  50. Radio observation of GRB 080520 with ATCA
  51. GRB 081105: Observations from OSN
  52. Swift-XRT observations of GRB 081105
  53. GRB 081101B: Fermi GBM detection
  54. Radio observation of GRB 080516 with ATCA
  55. GRB 081105 Swift/BAT and IPN Localization
  56. GRB 081025: Fermi GBM observation
  57. GRB 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
  58. GRB 081104: refined XRT analysis
  59. GRB 081104: Enhanced Swift-XRT position
  60. GRB 081104: Swift-BAT refined analysis
  61. GRB 081104 : Faulkes Telescope South observations
  62. Radio observation of GRB 080130 with ATCA
  63. GRB 081102: MASTER prompt optical limit
  64. GRB 081102: Swift-XRT refined analysis
  65. GRB 081102: Swift-BAT refined analysis
  66. GRB 081102: Enhanced Swift-XRT position
  67. Radio observation of GRB 080218b with ATCA
  68. Radio observation of GRB 080229a with ATCA
  69. GRB 081102: MASTER VWF promt observation
  70. GRB 081102: Swift detection of a burst
  71. SGR 0501+4516: optical observations in August
  72. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  73. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  74. GRB 081024B: BTA deep optical observations
  75. GRB 081024B: new Swift-XRT observations
  76. Radio observation of GRB 080229b with ATCA
  77. GRB 081024B: VLA radio observation
  78. GRB 081029: UVOT Detection of the Optical Afterglow
  79. GRB 081029: Swift-BAT refined analysis
  80. GRB081029: Swift XRT refined analysis
  81. GRB 081025: Suzaku WAM observation of the prompt emission
  82. GRB 081029: Enhanced Swift-XRT position
  83. GRB 081028: GROND Confirmation of the Optical/NIR Afterglow
  84. GRB 081029: REM observations
  85. Radio observation of GRB 080303 with ATCA
  86. Radio observation of GRB 080411 with ATCA
  87. GRB 081029: GROND Detection of the Optical/NIR Afterglow
  88. GRB 081029: ROTSE-III Detection of Optical Counterpart
  89. GRB 081028B: Fermi GBM detection
  90. GRB 081021: Fermi GBM detection
  91. Swift UVOT observations of GRB081028
  92. GRB 081028: Swift-XRT refined analysis
  93. GRB 081028, Swift-BAT refined analysis
  94. GRB 081028: Enhanced Swift-XRT position
  95. GRB 081028: TAROT Calern observatory optical observations
  96. GRB 081028: optical observations at the NOT
  97. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  98. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  99. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  100. GRB 081028: Swift detection of a burst

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