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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"
  1. GRB 130907A: VLA detection
  2. GRB 130907A: Swift-XRT refined Analysis
  3. GRB 130907A: Enhanced Swift-XRT position
  4. Errata of GRB name in GCN 15196: should have been GRB 130907A instead of GRB 120916A
  5. GRB 120916A: Fermi-LAT detection of a burst
  6. GRB 130907A: Swift/UVOT Detection
  7. GRB 130907A: Early Tautenburg detections, red afterglow
  8. GRB 130907A: Skynet DSO-14/Yerkes-41/GORT confirmation of a fading afterglow
  9. GRB 130907A: RATIR Optical and NIR Afterglow Confirmation
  10. GRB 130907A: Skynet DSO-14/Yerkes-41 detections of a possible afterglow
  11. GRB 130831A: Maidanak optical observations
  12. GRB 130831A: optical observation in Chuguev AO
  13. GRB 130831A: ISON-Kislovodsk optical observations
  14. GRB 130907A: NOT redshift
  15. GRB 130831A: optical observation in Gissar AO
  16. GRB 130831A: ISON-UAFO optical observations
  17. GRB 130907A: MASTER early OT observations
  18. GRB 130907A: Swift detection of a burst with an optical counterpart
  19. Swift follow-up results of the possible weak INTEGRAL GRB
  20. GRB 130903A: Swift/UVOT Upper Limits
  21. Swift follow-up of an INTEGRAL possible weak GRB
  22. GRB 130831A: RATIR Optical and NIR Upper Limits
  23. GRB 130822A: nearby galaxy redshifts
  24. GRB 130903A: GROND Afterglow Discovery
  25. GRB 130903A: MASTER early optical limit
  26. GRB 130903A: Fermi GBM observation
  27. GRB 130831A: JCMT SCUBA-2 sub-mm observation
  28. GRB 130903A: Swift-XRT observations
  29. Swift trigger 569022 is a new Galactic source Swift J1734.5-3027
  30. GRB 130903A: ISON-Kislovodsk optical Upper Limits
  31. GRB 130903A: GROND Upper Limits
  32. GRB 130903A: A long GRB detected by INTEGRAL
  33. GRB 130831A: Swift/UVOT Observations
  34. GRB 130831A: Montarrenti Observatory optical follow-up
  35. GRB 130831A: Optical Observations via Virtual Telescope, follow-up
  36. GRB 130831A: RATIR Optical and NIR Observations
  37. GRB 130831A: Continued Skynet/PROMPT-SSO, PROMPT-CTIO and Yerkes-41 detections
  38. GRB 130831B, Swift-BAT refined analysis
  39. GRB 130831A: VLA Observations
  40. GRB 130831A: T100 observations
  41. GRB 130831B: Swift/UVOT Upper Limits
  42. GRB 130831A: CARMA mm upper limit
  43. GRB 130831B: GROND upper limits
  44. Swift Trigger 569022: a possible GRB
  45. GRB 130831A: THO optical observation
  46. GRB 130831A, Swift-BAT refined analysis
  47. GRB 130831B: Swift-XRT refined Analysis
  48. GRB 130831A: optical observations
  49. GRB 130831A: Optical Observations via Virtual Telescope
  50. GRB 130831A: Swift-XRT refined Analysis
  51. GRB 130831A: Montarrenti Observatory optical observations
  52. GRB 130831B: Enhanced Swift-XRT position
  53. GRB 130831A: Skynet/PROMPT-SSO detections
  54. GRB 130831A: Enhanced Swift-XRT position
  55. GRB 130831A : Xinglong 60cm optical observation
  56. Konus-Wind observation of GRB 130831A
  57. GRB 130831A: Gemini-North Redshift
  58. GRB 130831A: MITSuME Akeno Optical observation
  59. GRB 130831A: Weihai optical observations
  60. GRB 130831B: Swift detection of a burst
  61. GRB 130831A: Faulkes Telescope North and South optical afterglow
  62. GRB 130831A: Swift detection of a burst with an optical counterpart
  63. IPN triangulation of GRB 130828A - error box
  64. GRB 130822A: optical upper limits
  65. GRB 130829A: AAO optical observations
  66. GRB 130828A: Swift XRT and UVOT observations
  67. GRB 130829A: NOT optical observations
  68. Correction to GCN 15132 - GRB 130828A
  69. IPN triangulation of GRB 130828A
  70. GRB 130829A: Swift detection of a burst
  71. GRB 130828A Tiled Swift observations
  72. GRB 130828A: Fermi GBM detection
  73. GRB 130828A: Fermi-LAT detection of a burst
  74. IPN triangulation of GRB130821A
  75. GRB 130822A Swift-BAT Spectral lag analysis
  76. Konus-Wind observation of GRB 130821A
  77. GRB 130821A: Weihai optical upper limit
  78. GRB 130821A: Swift-XRT observation
  79. GRB 130822A: 5.8 GHz VLA upper limit
  80. GRB 130822A: Gemini Observations
  81. GRB 130822A: Swift-XRT refined Analysis
  82. GRB 130822A: WHT ACAM observations
  83. GRB 130822A: Swift/UVOT Upper Limits
  84. GRB 130822A: Enhanced Swift-XRT position
  85. GRB 130822A, Swift-BAT refined analysis
  86. GRB 130821A: Fermi-LAT detection of a burst
  87. GRB 130822A: Weihai optical upper limit
  88. GRB 130821A: Fermi GBM Detection
  89. GRB 130822A: Swift detection of a short burst
  90. GRB 130816A: Swift/UVOT Upper Limits
  91. GRB 130816B: Swift/UVOT Upper Limits
  92. Fermi Gamma-ray Burst Monitor trigger 398555975 / 130818916 is not a GRB
  93. GRB 130816B, Swift-BAT refined analysis
  94. GRB 130816B: GROND afterglow candidate
  95. GRB 130816A: Swift-XRT refined Analysis
  96. GRB 130816A, Swift-BAT refined analysis
  97. GRB 130816A: Fermi GBM observation
  98. GRB 130816B: Swift-XRT refined Analysis
  99. GRB 130816B: Enhanced Swift-XRT position
  100. GRB 130816A: GROND confirmation of afterglow

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