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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. GRB 131030A - Liverpool Telescope Optical Afterglow Confirmation
  2. GRB 131030A: MASTER optical observation
  3. GRB 131029A: Swift-XRT follow up
  4. GRB 131030A: Watcher OT detection
  5. GRB 131030A: Swift detection of a burst with an optical counterpart
  6. GRB 131029A: Fermi GBM observation
  7. GRB 131029A Tiled Swift observations
  8. GRB 131029A: Fermi-LAT detection of a burst
  9. Konus-Wind observation of GRB 131028A
  10. IPN Triangulation of GRB 131028A (long/bright)
  11. GRB 131028A: Fermi GBM detection
  12. GRB 131011A: ATCA 34GHz upper limit
  13. Swift 575905/GRB 131026A: optical observations
  14. Swift-BAT Trigger 575905 is probably not a real source
  15. GRB 131024B: AAO optical upper limit
  16. GRB 131024B: Mondy optical upper limits
  17. GRB 131024B: MASTER prompt optical observation
  18. Swift Trigger 575905/ GRB 131026A: MITSuME Okayama and Ishigakijima Optical upper limits
  19. Swift Trigger 575905/possible GRB 131026A: Swift-XRT observations
  20. Swift Trigger 575905: ROTSE-III Optical Limits
  21. Swift Trigger 575905: KAIT Optical Upper Limit
  22. GRB 131026A: TAROT La Silla observatory optical observations
  23. Swift Trigger 575905: a possible GRB
  24. GRB 131024B, Swift-BAT refined analysis
  25. GRB 131024B: Fermi GBM observation
  26. GRB 131024B: RATIR Optical and NIR Observations
  27. GRB 131024B: Swift/UVOT Upper Limits
  28. GRB 131024B : Xinglong TNT upper limit
  29. GRB 131024B: Swift-XRT refined Analysis
  30. Fermi GBM trigger 13121024.436 is not a GRB
  31. GRB 131024B: Nanshan optical upper limit
  32. GRB 131024A: Swift/UVOT Upper Limits
  33. GRB 131024B: Enhanced Swift-XRT position
  34. GRB 131024A: GROND upper limits
  35. GRB 131024A: Swift-XRT refined Analysis
  36. GRB 131024B: Swift detection of a burst
  37. GRB 131024A, Swift-BAT refined analysis
  38. GRB 131024A: Skynet R-COP optical observations
  39. Konus-Wind observation of GRB 131011B
  40. GRB 131024A: Enhanced Swift-XRT position
  41. IPN triangulation of GRB 131011B (Swift Trigger 574266)
  42. GRB 131024A: Swift detection of a burst
  43. GRB 131014A: RATIR Optical/NIR Afterglow Retraction
  44. IPN Triangulation of GRB 131014A
  45. GRB 131018B: Swift/UVOT Upper Limits
  46. GRB 131018B: Swift-XRT observations
  47. GRB 131018B: Fermi GBM observation
  48. GRB 131018A: RATIR Optical and NIR Observations
  49. GRB 131018A: Swift/UVOT Upper Limits
  50. GRB 131018B: Fermi-LAT detection of a burst
  51. GRB 131018A: Swift-XRT refined Analysis
  52. GRB 131018A: KAIT Optical Upper Limit
  53. GRB 131018A, Swift-BAT refined analysis
  54. GRB 131018A: P60 Observations
  55. GRB 131018A: Enhanced Swift-XRT position
  56. GRB 131014A: XRT position information
  57. GRB131018A, optical observations
  58. GRB 131018A: Swift detection of a burst
  59. GRB 131014A: Suzaku WAM observation of the prompt emission
  60. GRB 131014A: GROND observations
  61. GRB 131014A: RATIR Optical/NIR Afterglow Confirmation
  62. Fermi GBM data availability during U.S. government shutdown
  63. GRB 131014A: Swift-XRT refined Analysis
  64. GRB 131011A: Swift/UVOT Upper Limits
  65. GRB 131014A: Swift/UVOT Upper Limits
  66. Fermi 403206457 / GRB 131011A: AAO optical observations
  67. GRB 131014A: RATIR Optical and NIR Observations
  68. GRB 131014A: Enhanced XRT position
  69. Konus-Wind observation of GRB 131014A
  70. GRB 131014A: NOT afterglow candidate
  71. GRB 131014A: Nanshan optical observations
  72. GRB 131014A: Swift detection of a possible X-ray afterglow
  73. GRB 131014A Tiled Swift observations
  74. GRB 131014A: Fermi-LAT detection
  75. GRB 131014A: Fermi GBM detection
  76. GRB 131011A: Fermi GBM detection
  77. iPTF 13dsw/Fermi403206457: X-Shooter redshift
  78. Swift-XRT detection of iPTF 13dsw/Fermi403206457
  79. GRB 131011A: GROND afterglow observations
  80. Fermi403206457: continued P60 observations and fading behavior
  81. Fermi403206457: Weihai optical upper limit
  82. Fermi403206457: NOT optical observations
  83. Fermi403206457: iPTF detection of a possible optical afterglow
  84. Trigger 574266 is not a Swift detection of a known source
  85. GRB 130925A: Possible signatures of binary nature in the afterglow - Request for observations
  86. GRB 130831A: Continued RATIR Optical and NIR Observations
  87. GRB 130831A: VLT/FORS2 spectroscopic detection of a supernova
  88. GRB 131004A: MOSFIRE NIR imaging
  89. GRB 131004A: Correction to XRT refined analysis
  90. GRB 131004A: Skynet PROMPT/DSO-14 upper limits
  91. GRB 131004A, Swift-BAT refined analysis
  92. GRB 131004A: Fermi GBM observation
  93. GRB 131004A: CARMA 93 GHz upper limit
  94. GRB 131004A: Swift/UVOT Detection
  95. GRB 131004A: RATIR Optical and NIR Upper Limits
  96. GRB 131004A: Swift-XRT refined Analysis
  97. GRB131004A: TNG Redshift confirmation
  98. GRB 131004A: GROND observations of the afterglow
  99. GRB 131004A: Enhanced Swift-XRT position
  100. GRB131004A: Magellan Redshift

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