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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"

28074 results found.

  1. Radio observation of GRB 081104 with ATCA
  2. Radio observation of GRB 081029 with ATCA
  3. Radio observation of GRB 081008 with ATCA
  4. GRB 081203B: Gemini observations
  5. GRB 081128: optical observation in CrAO
  6. GRB 081128: Optical afterglow observations
  7. GRB 081204: GROND Observations
  8. GRB081203B: optical observations
  9. Radio detection of GRB 081203B with the VLA
  10. GRB 081204: Magellan observations
  11. GRB081203A: Radio upper limit at 15 GHz
  12. GRB 081204B: Fermi GBM detection
  13. GRB 081204: Swift/UVOT Upper Limits
  14. GRB 081204: Swift XRT afterglow confirmation
  15. GRB081203A: MITSuME optical observation
  16. GRB 081203A: Optical observations of Xinglong TNT telescope
  17. GRB 081203A: Skynet/GORT Detections
  18. GRB 081204: Swift XRT afterglow candidate
  19. GRB081203A: optical observation
  20. VLA Radio upper limit on GRB 081203A
  21. Swift-XRT observations of GRB 081203B
  22. GRB081203A: Swift-XRT refined analysis
  23. GRB 081203B: optical observations
  24. GRB 081203B: SDSS upper limits at the position of the optical afterglow
  25. Swift/UVOT detection of GRB081203B
  26. GRB 081203B: Swift-XRT candidate afterglow.
  27. GRB 081203A: optical observations
  28. Swift UVOT observations of GRB 081203A
  29. GRB 081203A: Burst detection from Swift-BAT slew data
  30. GRB 081203: Enhanced Swift-XRT position
  31. GRB081203: optical observation
  32. GRB 081203: Swift detection of a burst with a bright optical counterpart
  33. GRB 081128: optical observation
  34. GRB 081130B: Fermi GBM detection
  35. GRB 081130: Fermi GBM detection
  36. GRB 081126: afterglow photometry
  37. GRB 081126: Fermi GBM detection
  38. VLA Radio upper limit on GRB 081126
  39. GRB 081129: Fermi GBM detection
  40. GRB 081128A: optical observations
  41. Swift Trigger 335971 is probably not a real source
  42. Trigger 335971: Swift possible detection of a burst
  43. GRB081128: Swift/UVOT Upper Limits
  44. SGR 1806-20: Fermi GBM detection.
  45. GRB 081122B: Fermi GBM Detection
  46. GRB 081128: Swift-XRT refined analysis
  47. GRB 081128: Liverpool Telescope afterglow confirmation
  48. GRB081128: optical observations
  49. GRB081128 : Lulin optical follow-ups
  50. GRB 081128: Enhanced Swift-XRT position
  51. GRB 081128: Optical observation of xinglong TNT
  52. GRB 081128: Swift detection of a burst
  53. GRB081126: Afterglow photometry from Crni Vrh
  54. GRB 081126: GRT Optical Observation
  55. GRB 081127: Swift/UVOT Upper Limits
  56. GRB 081127: Swift-XRT refined analysis
  57. GRB 081127: Enhanced Swift-XRT position
  58. GRB 081126: Confirmation of the Optical Afterglow
  59. GRB 081126: Swift-XRT refined analysis
  60. GRB 081127: Swift detection of a burst
  61. GRB 081126: Swift/UVOT Observations
  62. GRB 081126: optical observations
  63. GRB 081126: Enhanced Swift-XRT position
  64. GRB 081126: TAROT Calern observatory optical observations
  65. GRB 081126: Swift detection of a burst
  66. GRB 081125: Fermi GBM detection
  67. GRB 081124: Fermi GBM detection
  68. GRB 081120: Fermi GBM detection
  69. GRB 081118: Fermi GBM detection.
  70. GRB 081122: Fermi GBM detection
  71. GRB 081121, SMARTS optical/IR afterglow observations
  72. GRB081121: Fermi GBM detection
  73. Fermi GBM detection of a weak source
  74. GRB081121: Refined Swift/UVOT observations
  75. GRB 081121: Swift-XRT refined analysis
  76. GRB 081121: Magellan Redshift
  77. GRB 081121: Enhanced Swift-XRT position
  78. GRB 081121: GROND observations
  79. GRB081121: Swift/UVOT observations
  80. GRB 081121: Swift detection of a burst
  81. GRB 081121: ROTSE-III Detection of Optical Counterpart
  82. GRB 081016b, SMARTS optical/IR observations
  83. GRB 081119: Fermi GBM detection
  84. VLA Radio upper limit on GRB 081118
  85. GRB 081118: VLT redshift
  86. GRB 081118: Swift-XRT refined analysis
  87. GRB 081118: GROND detection of afterglow
  88. GRB 081118: optical afterglow candidate
  89. GRB 081118: Swift UVOT Upper Limits
  90. GRB 081118: Enhanced Swift-XRT position
  91. GRB 081118: Swift detection of a burst
  92. GRB 081109A: confirmation of possible detection host galaxy
  93. Further Swift-XRT observations of the probable GRB 081105.
  94. GRB 081113: Fermi GBM detection
  95. GRB 081102: RTT150 Optical observations
  96. GRB 081110: Fermi GBM detection
  97. GRB 081109: TAROT La Silla observatory optical observations
  98. GRB 081102: MASTER refind and final results
  99. GRB 081109: GROND redshift limit and host extinction
  100. GRB 081025: Swift-XRT further analysis

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