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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"

45437 results found.

  1. GRB 111121A: Swift-XRT refined Analysis
  2. GRB 111121A: Swift-BAT refined analysis
  3. GRB 111117A: Chandra detection of the afterglow
  4. GRB 111121A: Enhanced Swift-XRT position
  5. GRB 111121A: Swift detection of a short hard burst
  6. GRB 111117A: Gemini Afterglow Limits
  7. GRB 111117A: optical upper limit in CrAO
  8. GRB 111117A: Fermi GBM observation
  9. GRB 111117A: further NOT observations
  10. GRB 111117A: EVLA observations
  11. GRB 111117A: TNG observations
  12. GRB 111117A: Swift/UVOT Upper Limits
  13. GRB 111117A: GROND observations
  14. GRB 111117A: Gemini host observation
  15. GRB111117A: Magellan IMACS observations
  16. GRB 111117A: Swift-XRT refined Analysis
  17. GRB111107A: Further ATCA observations - no detection
  18. GRB 111117A: NOT observations
  19. GRB 111117A: Chandra ToO observation scheduled
  20. GRB 111117A: Swift-BAT refined analysis of a short hard burst
  21. GRB 111117A: GMG upper limit
  22. GRB 111117A: Swift detection of a short hard burst
  23. GRB111107A: ATCA observations - upper limit and a possible detection
  24. Konus-Wind observation of GRB 111113A
  25. IPN Triangulation of GRB 111113A (short/hard/intense)
  26. XRF 111111A/MAXI J0158-744: MAXI GSC refined analysis
  27. XRF 111111A/MAXI J0158-744: MAXI GSC and SSC detection of a soft X-ray transient near SMC
  28. GRB 111109A: Swift-XRT refined Analysis
  29. GRB 111109A: Swift/UVOT Photometry
  30. GRB 111109A: Swift-BAT refined analysis
  31. GRB 111109A: Enhanced Swift-XRT position
  32. GRB 111109A: Swift-XRT observations
  33. GRB 111109A: Swift detection of a burst
  34. GRB 111103B: optical upper limit of CrAO
  35. GRB 111103B: optical upper limit of Mt. Terskol observatory
  36. GRB 111107A: Fermi GBM observation
  37. Continued Skynet observations of GRB111107A
  38. GRB 111107A: Swift-XRT refined Analysis
  39. GRB 111107A: VLT/X-shooter spectroscopy
  40. GRB 111107A: APEX submm observation
  41. GRB 111107A: Swift/UVOT Afterglow Analysis
  42. GRB 111107A: Swift-BAT refined analysis
  43. GRB 111107A: Enhanced Swift-XRT position
  44. GRB 111107A: Gemini-South Redshift
  45. GRB 111107A: GROND observations
  46. Skynet observations of GRB 111107A
  47. GRB 111107A: Swift detection of a burst with an optical counterpart
  48. GRB 111103B: MITSuME Akeno Optical upper limits
  49. Konus-Wind observation of GRB 111103B
  50. GRB 111103B : WIYN 3.5m NIR observations
  51. GRB 111103B: Swift-XRT refined Analysis
  52. GRB 111103A: Fermi GBM observation
  53. GRB111103B Swift/UVOT Upper Limits
  54. GRB 111103B: optical observations from TAU, Ka-Dar
  55. Trigger 506913: MASTER detection of Swift J1922.7-1716 optical counterpart
  56. GRB 111103B: Enhanced Swift-XRT position
  57. GRB 111103B: Swift-BAT refined analysis
  58. GRB 111103A: Swift-BAT refined analysis
  59. Trigger 506913: Swift detection of Swift J1922.7-1716 and its optical counterpart
  60. GRB 111022B: MASTER OT observations
  61. GRB 111103B: optical observations
  62. GRB 111103B: Swift detection of a strong burst from a GRB or Galactic source
  63. GRB 111103A: Swift detection of a burst
  64. Swift-BAT trigger 506884 is not a GRB
  65. GRB 111029A: RAPTOR Limits During the Gamma-ray Emitting Interval
  66. GRB 111029A: SAO RAS optical limits
  67. GRB 111029A: Super-LOTIS early limits
  68. All GCN Circulars available in a tarfile for data mining
  69. GRB 111026A: spectral lag value inconclusive for a short burst
  70. GRB111029A: MITSuME Ishigakijima Optical Upper Limits
  71. GRB 111029A: TNT optical upper limit, Correction to GCN 12503
  72. GRB 111029A: Swift-XRT refined Analysis
  73. GRB 111029A: PAIRITEL NIR Upper Limits
  74. GRB 111026A: Swift-BAT refined analysis
  75. GRB 111029A: Swift/UVOT Upper Limits
  76. GRB 111029A: KAIT optical limits
  77. GRB 111029A: Swift-BAT refined analysis
  78. GRB 111029A: TNT optical upper limit
  79. GRB 111029A: Enhanced Swift-XRT position
  80. GRB 111029A: Faulkes Telescope North observations
  81. GRB 111029A: optical upper limit
  82. GRB 111029A: ROTSE-III Optical Limits
  83. GRB 111029A: Swift detection of a burst
  84. GRB 111026A: Swift detection of a burst
  85. GRB 111022B: EVLA observations - correction to GCN 12495
  86. GRB 111022B: EVLA observations
  87. GRB 111022B: 10.4m GTC z'-band observations
  88. GRB111022B: D50 optical limit
  89. GRB 111020A: Chandra Observation
  90. GRB 111022B: BTA Optical Observations
  91. GRB 111022A: MITSuME Akeno Optical upper limits
  92. GRB 111024A: MAXI/GSC detection of a burst
  93. GRB 111022B: Swift/UVOT upper limits
  94. GRB 111022A: Swift/UVOT Upper Limits
  95. GRB 111016A: optical upper limit
  96. GRB 111022B, Swift-BAT refined analysis
  97. GRB 111022B: Swift-XRT refined Analysis
  98. GRB 111022A: RIzY Observation
  99. GRB 111022A: Swift-XRT refined Analysis
  100. GRB 111022B: Gemini infrared observations

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