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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"

28061 results found.

  1. GRB 111123A: GMG optical observation
  2. GRB 111123A: Swift detection of a burst
  3. GRB 111117A, the review of the sky area in plate archives
  4. GRB 111121A: Swift/UVOT Upper Limits
  5. GRB 111121A: Magellan/Megacam observations
  6. GRB 111121A: Swift-XRT refined Analysis
  7. GRB 111121A: Swift-BAT refined analysis
  8. GRB 111117A: Chandra detection of the afterglow
  9. GRB 111121A: Enhanced Swift-XRT position
  10. GRB 111121A: Swift detection of a short hard burst
  11. GRB 111117A: Gemini Afterglow Limits
  12. GRB 111117A: optical upper limit in CrAO
  13. GRB 111117A: Fermi GBM observation
  14. GRB 111117A: TNG observations
  15. GRB 111117A: Swift/UVOT Upper Limits
  16. GRB 111117A: GROND observations
  17. GRB 111117A: Gemini host observation
  18. GRB 111117A: Swift-XRT refined Analysis
  19. GRB 111117A: NOT observations
  20. GRB 111117A: Chandra ToO observation scheduled
  21. GRB 111117A: Swift-BAT refined analysis of a short hard burst
  22. GRB 111117A: GMG upper limit
  23. GRB 111117A: Swift detection of a short hard burst
  24. GRB111107A: ATCA observations - upper limit and a possible detection
  25. IPN Triangulation of GRB 111113A (short/hard/intense)
  26. XRF 111111A/MAXI J0158-744: MAXI GSC and SSC detection of a soft X-ray transient near SMC
  27. GRB 111109A: Swift-XRT refined Analysis
  28. GRB 111109A: Swift/UVOT Photometry
  29. GRB 111109A: Swift-BAT refined analysis
  30. GRB 111109A: Enhanced Swift-XRT position
  31. GRB 111109A: Swift-XRT observations
  32. GRB 111109A: Swift detection of a burst
  33. GRB 111103B: optical upper limit of CrAO
  34. GRB 111103B: optical upper limit of Mt. Terskol observatory
  35. GRB 111107A: Fermi GBM observation
  36. Continued Skynet observations of GRB111107A
  37. GRB 111107A: Swift-XRT refined Analysis
  38. GRB 111107A: APEX submm observation
  39. GRB 111107A: Swift/UVOT Afterglow Analysis
  40. GRB 111107A: Swift-BAT refined analysis
  41. GRB 111107A: Enhanced Swift-XRT position
  42. GRB 111107A: GROND observations
  43. Skynet observations of GRB 111107A
  44. GRB 111107A: Swift detection of a burst with an optical counterpart
  45. GRB 111103B : WIYN 3.5m NIR observations
  46. GRB 111103B: Swift-XRT refined Analysis
  47. GRB 111103A: Fermi GBM observation
  48. GRB111103B Swift/UVOT Upper Limits
  49. GRB 111103B: Enhanced Swift-XRT position
  50. GRB 111103B: Swift-BAT refined analysis
  51. GRB 111103A: Swift-BAT refined analysis
  52. Trigger 506913: Swift detection of Swift J1922.7-1716 and its optical counterpart
  53. GRB 111103B: Swift detection of a strong burst from a GRB or Galactic source
  54. GRB 111029A: RAPTOR Limits During the Gamma-ray Emitting Interval
  55. GRB 111029A: SAO RAS optical limits
  56. GRB 111029A: Super-LOTIS early limits
  57. All GCN Circulars available in a tarfile for data mining
  58. GRB111029A: MITSuME Ishigakijima Optical Upper Limits
  59. GRB 111029A: Swift-XRT refined Analysis
  60. GRB 111029A: PAIRITEL NIR Upper Limits
  61. GRB 111026A: Swift-BAT refined analysis
  62. GRB 111029A: Swift/UVOT Upper Limits
  63. GRB 111029A: Swift-BAT refined analysis
  64. GRB 111029A: Enhanced Swift-XRT position
  65. GRB 111029A: optical upper limit
  66. GRB 111029A: ROTSE-III Optical Limits
  67. GRB 111029A: Swift detection of a burst
  68. GRB 111026A: Swift detection of a burst
  69. GRB 111022B: 10.4m GTC z'-band observations
  70. GRB111022B: D50 optical limit
  71. GRB 111020A: Chandra Observation
  72. GRB 111022B: BTA Optical Observations
  73. GRB 111022B: Swift/UVOT upper limits
  74. GRB 111022A: Swift/UVOT Upper Limits
  75. GRB 111016A: optical upper limit
  76. GRB 111022B, Swift-BAT refined analysis
  77. GRB 111022B: Swift-XRT refined Analysis
  78. GRB 111022A: Swift-XRT refined Analysis
  79. GRB 111022B: NOT observations
  80. GRB 111022B: Enhanced Swift-XRT position
  81. GRB 111022A: Swift-BAT refined analysis
  82. GRB 111022A: Preliminary UVOT TDRSS Non-Detection
  83. GRB 111022B: Swift detection of a burst
  84. GRB 111022A: Swift detection of a burst
  85. GRB 111020A: Gemini-South additional observations and limit on an optical afterglow
  86. GRB 111020A: EVLA observations
  87. GRB 111020A: Swift-XRT refined Analysis
  88. GRB 111020A: Swift/UVOT Upper Limits
  89. GRB 111020A: Faulkes Telescope South observations
  90. GRB 111020A: Swift-BAT refined analysis
  91. GRB 111020A: Enhanced Swift-XRT position
  92. GRB 111020A: BOOTES-3 Optical Upper Limit.
  93. GRB 111020A: Swift detection of a short burst
  94. GRB 111018A: Swift/UVOT Upper Limits
  95. GRB 111018A: Swift-BAT refined analysis
  96. GRB 111018A: Swift-XRT refined Analysis
  97. GRB 111018A: GROND Upper Limits
  98. GRB 111018A: Enhanced Swift-XRT position
  99. IPN Triangulation of GRB 111016B (long duration, intense)
  100. GRB111016A : WIYN 3.5m NIR observations

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