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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"

27475 results found.

  1. Radio observation of GRB 081109 with ATCA
  2. Radio observation of GRB 081104 with ATCA
  3. Radio observation of GRB 081029 with ATCA
  4. Radio observation of GRB 081008 with ATCA
  5. GRB 081203B: Gemini observations
  6. GRB 081128: optical observation in CrAO
  7. GRB 081128: Optical afterglow observations
  8. GRB 081204: GROND Observations
  9. GRB081203B: optical observations
  10. Radio detection of GRB 081203B with the VLA
  11. GRB 081204: Magellan observations
  12. GRB081203A: Radio upper limit at 15 GHz
  13. GRB 081204B: Fermi GBM detection
  14. GRB 081204: Swift/UVOT Upper Limits
  15. GRB 081204: Swift XRT afterglow confirmation
  16. GRB081203A: MITSuME optical observation
  17. GRB 081203A: Optical observations of Xinglong TNT telescope
  18. GRB 081203A: Skynet/GORT Detections
  19. GRB 081204: Swift XRT afterglow candidate
  20. GRB081203A: optical observation
  21. VLA Radio upper limit on GRB 081203A
  22. Swift-XRT observations of GRB 081203B
  23. GRB081203A: Swift-XRT refined analysis
  24. GRB 081203B: optical observations
  25. GRB 081203B: SDSS upper limits at the position of the optical afterglow
  26. Swift/UVOT detection of GRB081203B
  27. GRB 081203B: Swift-XRT candidate afterglow.
  28. GRB 081203A: optical observations
  29. Swift UVOT observations of GRB 081203A
  30. GRB 081203A: Burst detection from Swift-BAT slew data
  31. GRB 081203: Enhanced Swift-XRT position
  32. GRB081203: optical observation
  33. GRB 081203: Swift detection of a burst with a bright optical counterpart
  34. GRB 081128: optical observation
  35. GRB 081130B: Fermi GBM detection
  36. GRB 081130: Fermi GBM detection
  37. GRB 081126: afterglow photometry
  38. GRB 081126: Fermi GBM detection
  39. VLA Radio upper limit on GRB 081126
  40. GRB 081129: Fermi GBM detection
  41. GRB 081128A: optical observations
  42. Swift Trigger 335971 is probably not a real source
  43. Trigger 335971: Swift possible detection of a burst
  44. GRB081128: Swift/UVOT Upper Limits
  45. SGR 1806-20: Fermi GBM detection.
  46. GRB 081122B: Fermi GBM Detection
  47. GRB 081128: Swift-XRT refined analysis
  48. GRB 081128: Liverpool Telescope afterglow confirmation
  49. GRB081128: optical observations
  50. GRB081128 : Lulin optical follow-ups
  51. GRB 081128: Enhanced Swift-XRT position
  52. GRB 081128: Optical observation of xinglong TNT
  53. GRB 081128: Swift detection of a burst
  54. GRB081126: Afterglow photometry from Crni Vrh
  55. GRB 081126: GRT Optical Observation
  56. GRB 081127: Swift/UVOT Upper Limits
  57. GRB 081127: Swift-XRT refined analysis
  58. GRB 081127: Enhanced Swift-XRT position
  59. GRB 081126: Confirmation of the Optical Afterglow
  60. GRB 081126: Swift-XRT refined analysis
  61. GRB 081127: Swift detection of a burst
  62. GRB 081126: Swift/UVOT Observations
  63. GRB 081126: optical observations
  64. GRB 081126: Enhanced Swift-XRT position
  65. GRB 081126: TAROT Calern observatory optical observations
  66. GRB 081126: Swift detection of a burst
  67. GRB 081125: Fermi GBM detection
  68. GRB 081124: Fermi GBM detection
  69. GRB 081120: Fermi GBM detection
  70. GRB 081118: Fermi GBM detection.
  71. GRB 081122: Fermi GBM detection
  72. GRB 081121, SMARTS optical/IR afterglow observations
  73. GRB081121: Fermi GBM detection
  74. Fermi GBM detection of a weak source
  75. GRB081121: Refined Swift/UVOT observations
  76. GRB 081121: Swift-XRT refined analysis
  77. GRB 081121: Magellan Redshift
  78. GRB 081121: Enhanced Swift-XRT position
  79. GRB 081121: GROND observations
  80. GRB081121: Swift/UVOT observations
  81. GRB 081121: Swift detection of a burst
  82. GRB 081121: ROTSE-III Detection of Optical Counterpart
  83. GRB 081016b, SMARTS optical/IR observations
  84. GRB 081119: Fermi GBM detection
  85. VLA Radio upper limit on GRB 081118
  86. GRB 081118: VLT redshift
  87. GRB 081118: Swift-XRT refined analysis
  88. GRB 081118: GROND detection of afterglow
  89. GRB 081118: optical afterglow candidate
  90. GRB 081118: Swift UVOT Upper Limits
  91. GRB 081118: Enhanced Swift-XRT position
  92. GRB 081118: Swift detection of a burst
  93. GRB 081109A: confirmation of possible detection host galaxy
  94. Further Swift-XRT observations of the probable GRB 081105.
  95. GRB 081113: Fermi GBM detection
  96. GRB 081102: RTT150 Optical observations
  97. GRB 081110: Fermi GBM detection
  98. GRB 081109: TAROT La Silla observatory optical observations
  99. GRB 081102: MASTER refind and final results
  100. GRB 081109: GROND redshift limit and host extinction

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