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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"

44269 results found.

  1. GRB 111026A: spectral lag value inconclusive for a short burst
  2. GRB111029A: MITSuME Ishigakijima Optical Upper Limits
  3. GRB 111029A: TNT optical upper limit, Correction to GCN 12503
  4. GRB 111029A: Swift-XRT refined Analysis
  5. GRB 111029A: PAIRITEL NIR Upper Limits
  6. GRB 111026A: Swift-BAT refined analysis
  7. GRB 111029A: Swift/UVOT Upper Limits
  8. GRB 111029A: KAIT optical limits
  9. GRB 111029A: Swift-BAT refined analysis
  10. GRB 111029A: TNT optical upper limit
  11. GRB 111029A: Enhanced Swift-XRT position
  12. GRB 111029A: Faulkes Telescope North observations
  13. GRB 111029A: optical upper limit
  14. GRB 111029A: ROTSE-III Optical Limits
  15. GRB 111029A: Swift detection of a burst
  16. GRB 111026A: Swift detection of a burst
  17. GRB 111022B: EVLA observations - correction to GCN 12495
  18. GRB 111022B: EVLA observations
  19. GRB 111022B: 10.4m GTC z'-band observations
  20. GRB111022B: D50 optical limit
  21. GRB 111020A: Chandra Observation
  22. GRB 111022B: BTA Optical Observations
  23. GRB 111022A: MITSuME Akeno Optical upper limits
  24. GRB 111024A: MAXI/GSC detection of a burst
  25. GRB 111022B: Swift/UVOT upper limits
  26. GRB 111022A: Swift/UVOT Upper Limits
  27. GRB 111016A: optical upper limit
  28. GRB 111022B, Swift-BAT refined analysis
  29. GRB 111022B: Swift-XRT refined Analysis
  30. GRB 111022A: RIzY Observation
  31. GRB 111022A: Swift-XRT refined Analysis
  32. GRB 111022B: Gemini infrared observations
  33. GRB 111022B: MITSuME Akeno Optical upper limits
  34. GRB 111022B: NOT observations
  35. GRB 111022B: Enhanced Swift-XRT position
  36. GRB 111020A Spectral lag analysis
  37. GRB 111022A: Swift-BAT refined analysis
  38. GRB 111022B: MASTER-Net early limit
  39. GRB 111022A: Preliminary UVOT TDRSS Non-Detection
  40. GRB 111022A: MASTER-Net early limit
  41. GRB 111022B: Swift detection of a burst
  42. GRB 111022A: Swift detection of a burst
  43. GRB 111020A: Gemini-South additional observations and limit on an optical afterglow
  44. GRB 111020A: EVLA observations
  45. GRB 111020A: Swift-XRT refined Analysis
  46. GRB 111020A: Gemini-South i-band observations
  47. GRB 111020A: Swift/UVOT Upper Limits
  48. GRB 111020A: Swift-BAT refined analysis
  49. GRB 111020A: Enhanced Swift-XRT position
  50. GRB 111020A: BOOTES-3 Optical Upper Limit.
  51. GRB 111020A: Planned XMM-Newton observation
  52. GRB 111020A: Swift detection of a short burst
  53. GRB 111018A: Swift/UVOT Upper Limits
  54. GRB 110918A: Optical light curve for days 1.4 to 16.3
  55. GRB 111018A: Swift-BAT refined analysis
  56. Konus-Wind observation of GRB 111016B
  57. GRB 111018A: Swift-XRT refined Analysis
  58. GRB 111018A: GROND Upper Limits
  59. GRB 111018A: Enhanced Swift-XRT position
  60. IPN Triangulation of GRB 111016B (long duration, intense)
  61. GRB111016A : WIYN 3.5m NIR observations
  62. GRB 111018A: Swift detection of a burst
  63. GRB 111017A: Fermi GBM Detection
  64. GRB111016A: D50 optical limit
  65. GRB 111016A: Gemini Detection of the NIR Counterpart
  66. GRB 111016A: Swift/UVOT Detection of a Source
  67. GRB 111016A: Swift-BAT refined analysis
  68. GRB 111016A: P60 Afterglow Candidate
  69. GRB 111016A: MITSuME Akeno Optical upper limits
  70. GRB 111016A: Swift-XRT refined Analysis
  71. GRB 111016A: Enhanced Swift-XRT position
  72. GRB 111016A: Swift-XRT observations
  73. GRB 111016A: Swift detection of a burst
  74. GRB 110921A: optical observations
  75. GRB 111008A : miniTAO/ANIR NIR observations
  76. EVLA 22 GHz Detection of GRB 111008A
  77. GRB 111005A: ATCA 18 GHz decay
  78. GRB 111008A: Swift/UVOT Upper Limits
  79. Konus-Wind observation of GRB 111008A
  80. GRB 111008A: IAC80 I-band observations
  81. GRB 111008A: VLT/X-shooter spectroscopy
  82. GRB 111008A: Swift-XRT refined Analysis
  83. GRB 111008A: Gemini spectroscopic redshift
  84. GRB 111008A, GROND observations
  85. GRB 111008A: NOT optical observation
  86. GRB 111008A: Gemini optical counterpart
  87. GRB 111008A: Enhanced Swift-XRT position
  88. GRB 111008A, Swift-BAT refined analysis,
  89. GRB 111008A: Swift detection of a burst
  90. GRB 111005A: ATCA 18 GHz detection
  91. GRB 111005A: ATCA radio upper limit
  92. GRB 111005A : miniTAO/ANIR NIR observations
  93. GRB 111005A: EVLA Observations
  94. GRB 111005A: VLT optical observations
  95. GRB 111005A: GROND NIR observations
  96. GRB 111005A: VLT IR observations
  97. GRB 111005A: Swift-BAT refined analysis
  98. GRB 111005A: bright galaxy in error circle
  99. GRB 111005A: Swift detection of a burst
  100. GRB 111003A: Fermi GBM detection

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