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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"

18429 results found.

  1. GRB 111103B: optical observations
  2. GRB 111103B: Swift detection of a strong burst from a GRB or Galactic source
  3. GRB 111103A: Swift detection of a burst
  4. Swift-BAT trigger 506884 is not a GRB
  5. GRB 111029A: RAPTOR Limits During the Gamma-ray Emitting Interval
  6. GRB 111029A: Swift-XRT refined Analysis
  7. GRB 111029A: PAIRITEL NIR Upper Limits
  8. GRB 111026A: Swift-BAT refined analysis
  9. GRB 111029A: Swift/UVOT Upper Limits
  10. GRB 111029A: KAIT optical limits
  11. GRB 111029A: Swift-BAT refined analysis
  12. GRB 111029A: Enhanced Swift-XRT position
  13. GRB 111029A: Faulkes Telescope North observations
  14. GRB 111029A: optical upper limit
  15. GRB 111029A: ROTSE-III Optical Limits
  16. GRB 111029A: Swift detection of a burst
  17. GRB 111026A: Swift detection of a burst
  18. GRB 111022B: EVLA observations - correction to GCN 12495
  19. GRB 111022B: EVLA observations
  20. GRB111022B: D50 optical limit
  21. GRB 111022A: MITSuME Akeno Optical upper limits
  22. GRB 111022B: Swift/UVOT upper limits
  23. GRB 111022A: Swift/UVOT Upper Limits
  24. GRB 111016A: optical upper limit
  25. GRB 111022B, Swift-BAT refined analysis
  26. GRB 111022B: Swift-XRT refined Analysis
  27. GRB 111022A: Swift-XRT refined Analysis
  28. GRB 111022B: NOT observations
  29. GRB 111022B: Enhanced Swift-XRT position
  30. GRB 111022A: Swift-BAT refined analysis
  31. GRB 111022B: MASTER-Net early limit
  32. GRB 111022A: Preliminary UVOT TDRSS Non-Detection
  33. GRB 111022A: MASTER-Net early limit
  34. GRB 111022B: Swift detection of a burst
  35. GRB 111022A: Swift detection of a burst
  36. GRB 111020A: Swift-XRT refined Analysis
  37. GRB 111020A: Swift/UVOT Upper Limits
  38. GRB 111020A: Swift-BAT refined analysis
  39. GRB 111020A: Enhanced Swift-XRT position
  40. GRB 111020A: BOOTES-3 Optical Upper Limit.
  41. GRB 111020A: Swift detection of a short burst
  42. GRB 111018A: Swift/UVOT Upper Limits
  43. GRB 111018A: Swift-BAT refined analysis
  44. GRB 111018A: Swift-XRT refined Analysis
  45. GRB 111018A: GROND Upper Limits
  46. GRB 111018A: Enhanced Swift-XRT position
  47. IPN Triangulation of GRB 111016B (long duration, intense)
  48. GRB 111018A: Swift detection of a burst
  49. GRB111016A: D50 optical limit
  50. GRB 111016A: Gemini Detection of the NIR Counterpart
  51. GRB 111016A: Swift/UVOT Detection of a Source
  52. GRB 111016A: Swift-BAT refined analysis
  53. GRB 111016A: P60 Afterglow Candidate
  54. GRB 111016A: Swift-XRT refined Analysis
  55. GRB 111016A: Enhanced Swift-XRT position
  56. GRB 111016A: Swift-XRT observations
  57. GRB 111016A: Swift detection of a burst
  58. GRB 110921A: optical observations
  59. EVLA 22 GHz Detection of GRB 111008A
  60. GRB 111008A: Swift/UVOT Upper Limits
  61. Konus-Wind observation of GRB 111008A
  62. GRB 111008A: Swift-XRT refined Analysis
  63. GRB 111008A, GROND observations
  64. GRB 111008A: Enhanced Swift-XRT position
  65. GRB 111008A, Swift-BAT refined analysis,
  66. GRB 111008A: Swift detection of a burst
  67. GRB 111005A: Swift-BAT refined analysis
  68. GRB 111005A: Swift detection of a burst
  69. GRB 110905A / MAXI J1836-194: optical monitoring
  70. GRB 110928A: RAPTOR Limits During Gamma-ray Emitting Interval
  71. GRB 110928A: Swift/UVOT Upper Limits
  72. Trigger 504307: Swift detection of MAXI J1836-194
  73. GRB 110928A: Swift-XRT refined Analysis
  74. GRB 110928A: Enhanced Swift-XRT position
  75. GRB 110928A: P60 Observations
  76. GRB 110928A: Further PAIRITEL NIR Observations
  77. GRB 110928A: Swift-BAT refined analysis
  78. GRB 110928A: Swift-XRT observations
  79. GRB 110928A: Swift/UVOT finding chart observation
  80. GRB 110928A: ROTSE-III Optical Limits
  81. GRB 110928A: Swift detection of a burst
  82. Swift-BAT trigger 503926 is noise
  83. GRB 110924A: Swift detection of a possible burst
  84. GRB 110921A: Swift/UVOT Observations
  85. GRB 110921A: NOT observations
  86. GRB 110921A: Fermi GBM observation
  87. GRB 110921A: Swift-XRT refined Analysis
  88. GRB 110921A, Swift-BAT refined analysis
  89. GRB 110921A: optical observations in Mt. Terskol and Maidanak observatories
  90. GRB 110921A: Enhanced Swift-XRT position
  91. GRB 110918A: Swift-XRT refined Analysis
  92. GRB 110921A: MASTER-Net early limit
  93. GRB 110921A: Swift detection of a burst
  94. GRB 110915B : X-ray afterglow confirmation
  95. GRB 110918A: Swift/UVOT Detection of the Optical Counterpart
  96. GRB 110918A: INT optical detection of Swift candidate afterglow
  97. GRB 110918A: Swift-XRT observations
  98. Swift detection of short bursts from PSR J1647-4552
  99. GRB 110915A: Konus-Wind and Swift/BAT joint spectral analysis
  100. IPN triangulation of GRB 110918A (long duration, extremely intense)

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