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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"

28062 results found.

  1. GRB081203A: Optical observations at Ishigaki
  2. GRB 081204: GROND Observations
  3. Radio detection of GRB 081203B with the VLA
  4. GRB081203A: Radio upper limit at 15 GHz
  5. GRB 081204B: Fermi GBM detection
  6. GRB 081204: Swift/UVOT Upper Limits
  7. GRB 081204: Swift XRT afterglow confirmation
  8. GRB081203A: MITSuME optical observation
  9. GRB081203A: optical observation
  10. GRB 081204 : a long GRB localized by INTEGRAL
  11. VLA Radio upper limit on GRB 081203A
  12. Swift-XRT observations of GRB 081203B
  13. GRB081203A: Swift-XRT refined analysis
  14. GRB 081203B: optical observations
  15. Swift/UVOT detection of GRB081203B
  16. GRB 081203B: Swift-XRT candidate afterglow.
  17. GRB 081203A: optical observations
  18. GRB081203A: Swift/UVOT grism redshift
  19. GRB 081203A: Burst detection from Swift-BAT slew data
  20. GRB 081203A: Swift-BAT refined analysis
  21. GRB 081203: Enhanced Swift-XRT position
  22. GRB 081130B: MASTER prompt optical observations
  23. GRB081203: optical observation
  24. GRB 081203: Swift detection of a burst with a bright optical counterpart
  25. GRB 081130B: Fermi GBM detection
  26. GRB 081130: Fermi GBM detection
  27. Swift Trigger 335971: Swift/UVOT Observations
  28. GRB 081126: afterglow photometry
  29. GRB 081126: Fermi GBM detection
  30. VLA Radio upper limit on GRB 081126
  31. GRB 081129: Fermi GBM detection
  32. GRB 081130: MASTER VWF prompt optical observations Fermi GRB
  33. GRB 081128A: optical observations
  34. Trigger 335971: Swift possible detection of a burst
  35. GRB081128: Swift/UVOT Upper Limits
  36. GRB 081122B: Fermi GBM Detection
  37. GRB 081128: Swift-XRT refined analysis
  38. GRB 081128: Liverpool Telescope afterglow confirmation
  39. GRB081128: optical observations
  40. GRB 081128: Swift-BAT refined analysis
  41. GRB 081128: Enhanced Swift-XRT position
  42. GRB 081128: Optical observation of xinglong TNT
  43. GRB 081128: Swift detection of a burst
  44. GRB081126: Afterglow photometry from Crni Vrh
  45. GRB 081126: GRT Optical Observation
  46. GRB 081127: Swift/UVOT Upper Limits
  47. GRB 081127: Swift-XRT refined analysis
  48. GRB 081127: Enhanced Swift-XRT position
  49. GRB 081127: Swift-BAT refined analysis
  50. GRB 081126: Swift-XRT refined analysis
  51. GRB 081127: Swift detection of a burst
  52. GRB 081126: Swift/UVOT Observations
  53. GRB 081126: optical observations
  54. GRB 081126: Swift-BAT refined analysis
  55. GRB 081126: Enhanced Swift-XRT position
  56. GRB 081126: TAROT Calern observatory optical observations
  57. GRB 081126: Swift detection of a burst
  58. GRB 081125: Fermi GBM detection
  59. GRB 081124: Fermi GBM detection
  60. GRB 081120: Fermi GBM detection
  61. GRB 081118: Fermi GBM detection.
  62. GRB 081122: Fermi GBM detection
  63. GRB 081121, SMARTS optical/IR afterglow observations
  64. Fermi GBM detection of a weak source
  65. GRB081121: Refined Swift/UVOT observations
  66. GRB 081121: Swift-XRT refined analysis
  67. GRB 081121: Enhanced Swift-XRT position
  68. GRB 081121: GROND observations
  69. GRB 081121: Swift-BAT refined analysis
  70. GRB081121: Swift/UVOT observations
  71. GRB 081121: ROTSE-III Detection of Optical Counterpart
  72. GRB081118 : optical upper limit
  73. GRB 081119: Fermi GBM detection
  74. VLA Radio upper limit on GRB 081118
  75. GRB 081118: Swift-XRT refined analysis
  76. GRB 081118: GROND detection of afterglow
  77. GRB 081118: optical afterglow candidate
  78. GRB 081118: Swift UVOT Upper Limits
  79. GRB 081118: Swift-BAT refined analysis
  80. GRB 081118: Enhanced Swift-XRT position
  81. GRB 081118: Swift detection of a burst
  82. GRB 081109A: confirmation of possible detection host galaxy
  83. Further Swift-XRT observations of the probable GRB 081105.
  84. GRB 081113: Fermi GBM detection
  85. GRB 081102: RTT150 Optical observations
  86. GRB 081110: Fermi GBM detection
  87. GRB 081109: TAROT La Silla observatory optical observations
  88. GRB 081102: MASTER refind and final results
  89. GRB 081109: GROND redshift limit and host extinction
  90. GRB 081025: Swift-XRT further analysis
  91. GRB 081024B: Swift-XRT late-time observations
  92. GRB 081109: GROND Detection of the Optical/NIR Afterglow Candidate
  93. GRB 081109A, Swift-BAT refined analysis
  94. GRB 081109A: Swift-XRT refined analysis
  95. GRB 081109: Fermi GBM detection
  96. Swift-BAT Trigger 334129: possible burst
  97. GRB 081109: REM NIR afterglow detection
  98. GRB 081109: Swift detection of a burst
  99. GRB 081024C: Fermi Gamma-ray Burst Monitor detection
  100. SGR 1806-20: Fermi GBM detection

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