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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 180115A: Swift/UVOT Detection
  2. GRB 180116A: Fermi GBM Detection
  3. Konus-Wind observation of GRB 180113B
  4. IPN Triangulation of GRB 180113B
  5. GRB 180112A: Insight-HXMT/HE detection/observation
  6. GRB 180111A AROMA-N optical observation
  7. Konus-Wind observation of GRB 180113C
  8. e-MERLIN detection of GRB 171205A
  9. IPN Triangulation of GRB 180113C
  10. GRB 180115A: Swift-BAT refined analysis
  11. GRB 180116A: MAXI/GSC detection
  12. GRB 180115A: Redshift from OSIRIS/GTC
  13. GRB 180115A: NOT detection of optical counterpart
  14. Konus-Wind observation of GRB 180113A
  15. GRB 180113C: Insight-HXMT/HE observation
  16. GRB 180113B: Insight-HXMT/HE observation
  17. GRB 180111A: Insight-HXMT/HE observation
  18. GRB 180115A: MITSuME Akeno optical upper limits
  19. GRB 180113A: Swift ToO observations
  20. GRB 180115A: Swift-XRT refined Analysis
  21. GRB 180115A: Enhanced Swift-XRT position
  22. Konus-Wind observation of GRB 180111A
  23. GRB 180115A: Swift detection of a burst with an optical counterpart.
  24. GRB 180113C: Fermi GBM detection
  25. GRB 180111A CALET Gamma-Ray Burst Monitor detection
  26. GRB 180113A: Swift-BAT refined analysis
  27. GRB 180111A: AbAO optical observations
  28. GRB 180113A: KAIT Optical Observations
  29. GRB 180113B: Fermi GBM detection
  30. GRB 180113A: Fermi GBM observation
  31. GRB 180111A: Swift/UVOT Detection
  32. GRB 180103A: Swift-XRT afterglow detection
  33. GRB 180113A: Swift detection of a burst
  34. GRB 180111A: Swift-BAT refined analysis
  35. GRB 180111A: RATIR Optical and NIR Observations
  36. GRB 180111A: Swift-XRT refined Analysis
  37. GRB 180111A: AGILE/MCAL detection
  38. GRB180111A: Xinglong TNT possible optical detection
  39. GRB 180111A: Enhanced Swift-XRT position
  40. GRB 180111A: Swift detection of a burst with an optical counterpart
  41. Correction to GCN Circular 22316: GRB 171230B: Insight-HXMT detection
  42. GRB 171230B: Insight-HXMT/HE detection
  43. GRB 180103A: LCO Sutherland 1-m telescope observations
  44. Konus-Wind observation of GRB 180103A
  45. GRB 171227A: AstroSat CZTI detection
  46. GRB 171223A; AstroSat CZTI detection
  47. Fermi GBM Trigger 537135776/180108849 is not a GRB
  48. GRB 180103A: AstroSat CZTI detection
  49. GRB 180103A: Swift/UVOT Upper Limits
  50. GRB 180103A: Swift-XRT observations
  51. GRB 171230A CALET Gamma-Ray Burst Monitor detection
  52. GRB 180103A: Swift ToO observations
  53. GRB 180103A: Swift detection of a burst
  54. GRB 171229A CALET Gamma-Ray Burst Monitor detection
  55. GRB 180102A AROMA-N optical observation
  56. VLBA detection of GRB 171205A
  57. GRB 180102A: TSHAO optical upper limit
  58. GRB 180102A: Swift-BAT refined analysis
  59. GRB 180102A: Swift/UVOT Upper Limits
  60. GRB 180102A: NOT optical observations
  61. GRB 180102A: MASTER-Net robotic report
  62. GRB 180102A: Swift-XRT refined Analysis
  63. GRB 180102A: Fermi GBM detection
  64. GRB 180102A: Enhanced Swift-XRT position
  65. GRB 180102A: Prompt enhanced Swift-XRT position
  66. GRB 180102A: Swift detection of a burst
  67. Konus-Wind observation of GRB 171227A
  68. IPN Triangulation of GRB 171227A
  69. GRB 171227A: Fermi GBM detection
  70. GRB 171227A: AGILE/MCAL detection
  71. GRB 171215A: Insight-HXMT/HE detection
  72. GRB 171223A: Insight-HXMT/HE detection
  73. GRB 171212C CALET Gamma-Ray Burst Monitor detection
  74. Konus-Wind observation of GRB 171216B
  75. IceCube-171106A: Konus-Wind upper limits
  76. IceCube-171015A: Konus-Wind upper limits
  77. IceCube-170922A: Konus-Wind upper limits
  78. GRB 171222A: Swift-BAT refined analysis
  79. GRB 171222A: AROMA-N optical observation
  80. GRB 171223A: Fermi GBM detection
  81. GRB 171222A: Fermi GBM detection
  82. GRB 171222A: Nanshan-0.36m optical upper limit
  83. GRB 171222A: Swift/UVOT Upper Limits
  84. GRB 171222A: Nanshan-1m optical afterglow detection
  85. GRB 171222A: MASTER-Net OT observations
  86. GRB 171222A: Redshift from 10.4m GTC/OSIRIS
  87. GRB 171222A: Swift-XRT refined Analysis
  88. GRB 171205A: SMARTS optical/IR supernova monitoring
  89. GRB 171222A: NOT Optical Afterglow
  90. GRB 171216B CALET Gamma-Ray Burst Monitor detection
  91. GRB 171210A CALET Gamma-Ray Burst Monitor detection
  92. GRB 171222A: Enhanced Swift-XRT position
  93. GRB 171222A: Swift detection of a burst
  94. GMRT Radio detection of GRB 171205A
  95. IPN Triangulation of GRB 171216B
  96. GRB 171216A: Swift/UVOT Upper Limits
  97. GRB 171210A: Further Swift-XRT observations
  98. GRB 171216A: Swift-XRT refined Analysis
  99. GRB 171216A: Swift-BAT refined analysis
  100. GRB 171205A: RATAN observations

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