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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. Trigger 643078: Swift detection of H1743-322
  2. Konus-Wind observation of GRB 150608A
  3. GRB 150608A: Swift-XRT afterglow detection
  4. Fermi Gamma-ray Burst Monitor trigger 455474712 / 150608698 is not a GRB
  5. GRB150607A: AAO and CrAO optical observations
  6. GRB150607A: Discovery Channel Telescope Optical Observations
  7. GRB 150608A: Tiled Swift observations
  8. GRB 150608A: MAXI/GSC detection
  9. Konus-Wind observation of GRB 150607A
  10. GRB 150607A: Swift-XRT refined Analysis
  11. GRB 150607A: Swift/UVOT Detection
  12. GRB 150607A: NOT optical observations
  13. GRB 150607A: Swift-BAT refined analysis
  14. GRB 150607A: Fermi GBM Detection
  15. GRB 150607A: Enhanced Swift-XRT position
  16. GRB 150607A: Swift detection of a burst with an optical counterpart
  17. GRB 150518A: possible SN observations
  18. Swift trigger 642453 is not an astrophysical source
  19. Swift Trigger 642453: a possible GRB
  20. Konus-Wind observation of GRB 150530A
  21. GRB 150530B: Swift-XRT observations
  22. GRB 150527A: Continued RATIR Observations
  23. Swift Triggers 642296 and 642297 are not GRBs
  24. GRB 150530B: Swift ToO observations
  25. GRB 150530B detected in ground analysis of BAT data
  26. GRB 150530A: RATIR Optical Observations
  27. GRB 150530A: Swift-XRT refined Analysis
  28. GRB 150530A: Swift/UVOT Upper Limits
  29. GRB 150530A: Fermi GBM observation
  30. GRB 150530A: Swift-BAT refined analysis
  31. GRB 150530A: Enhanced Swift-XRT position
  32. GRB 150530A: Swift detection of a burst
  33. Fermi GBM trigger 150529948 is not a GRB
  34. GRB 150513A: Swift-XRT observations
  35. Konus-Wind observation of GRB 150527A
  36. GRB 150527A: Swift-XRT refined Analysis
  37. GRB 150527A: MITSuME Okayama upper limits
  38. GRB 150527A: Swift/UVOT Upper Limits
  39. GRB150527A: REM - NIR afterglow
  40. GRB 150527A: Swift-BAT refined analysis
  41. GRB 150527A: Enhanced Swift-XRT position
  42. GRB 150527A: Fermi GBM observation
  43. GRB 150527A: LCOGT McDonald observations
  44. GRB 150527A: RATIR Afterglow Detection
  45. GRB 150523A: Suzaku WAM observation of the prompt emission
  46. GRB 150527A: Swift detection of a burst
  47. GRB 150523A: Swift ToO observations
  48. GRB 150523A: Swift/UVOT Detection
  49. GRB 150513A: request for X-ray follow up
  50. Konus-Wind observation of GRB 150523A
  51. GRB 150523A: LCOGT FTS afterglow confirmation
  52. GRB 150523A: LCOGT Cerro-Tololo optical afterglow candidate
  53. Confirmation that Swift Trigger 641332 is not astrophysical
  54. GRB 150523A Swift-XRT afterglow detection
  55. GRB 150523B: Swift ToO observations
  56. GRB 150523A: Fermi-LAT detection
  57. GRB 150523A: Fermi GBM detection
  58. Swift trigger 641332 is probably not an astrophysical source
  59. GRB 150518A: Continued RATIR optical observations
  60. GRB 150518A: MAXI-GSC further analysis
  61. GRB 150518A: 6.0 GHz VLA detection
  62. Disreqard the recent cluster of Swift-related GCN Circulars
  63. GRB 150518A: MITSuME Akeno Optical observation
  64. GRB 150518A: Mondy optical observations
  65. GRB 150518A: AMI 15 GHz detection of possible radio counterpart
  66. GRB 150518A: MASTER-net before, early and after optical stereoscopic observations with possible MP discovery inside MAXI error box
  67. Konus-Wind observation of GRB 150518A
  68. GRB 150518A: Swift-XRT follow-up observations
  69. GRB 150518A : Xinglong TNT upper limit
  70. GRB 150518A: SAO RAS optical observations
  71. GRB 150518A: Correction
  72. GRB 150518A: VLT/X-shooter redshift of the likely host galaxy
  73. GRB 150518A: RATIR optical observations
  74. GRB 150518A: GMG observation
  75. GRB 150518A: Xinglong2.16m optical afterglow detection
  76. Swift/UVOT observations of GRB150518A
  77. GRB 150518A: Swift-XRT afterglow detection
  78. GRB 150518A: Tiled Swift observations
  79. GRB 150518A: MAXI/GSC detection
  80. GRB 150514A: Further Swift observations
  81. Konus-Wind observation of GRB 150514A
  82. GRB 150514A: VLT/X-shooter redshift
  83. GRB 150514A: GROND Bright Afterglow Confirmation
  84. GRB 150514A: Swift/UVOT Detection
  85. GRB 150514A: Fermi GBM Detection
  86. GRB 150514A: Swift-XRT afterglow detection
  87. GRB 150514A: Swift ToO observations
  88. GRB 150514A: Fermi-LAT detection
  89. GRB 150512A: CrAO optical observations
  90. GRB 150513A: Swift-BAT refined analysis
  91. GRB 150513A: Fermi GBM detection
  92. GRB 150513A: Fermi-LAT detection
  93. GRB 150512A: Fermi GBM detection
  94. GRB 150513A: Swift detection of a burst
  95. GRB 150512A: iPTF Optical Observations
  96. Konus-Wind observation of GRB 150510A
  97. GRB 150510A: Fermi GBM detection
  98. GRB 150510A: Fermi-LAT Refined Analysis
  99. GRB 150510A: Fermi-LAT detection
  100. GRB 150424A: 9.8 GHz VLA detection

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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