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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 220623A: Swift-XRT refined Analysis
  2. GRB 220623A: NOT optical observations
  3. GRB 220623A: Swift/UVOT Upper Limits
  4. GRB 220623A: BOOTES-5/JGT optical afterglow detection
  5. Konus-Wind detection of GRB 220609B
  6. GRB 220623B: Fermi GBM Final Real-time Localization
  7. GRB 220623A: Enhanced Swift-XRT position
  8. GRB 220623A: AGILE detection
  9. GRB 220623A: AstroSat CZTI detection
  10. GRB 220623A: iTelescope optical upper limit
  11. GRB 220623A: Swift-XRT observations
  12. GRB 220623A: Swift detection of a burst
  13. Fermi trigger No 677597318: Global MASTER-Net observations report
  14. GRB 220618A: Fermi GBM detection
  15. Swift Detection of MAXI J0655-013
  16. GRB 220618A: Swift-BAT refined analysis
  17. GRB 220618A: iTelescope T-19 upper limit
  18. Konus-Wind detection of GRB 220617A
  19. Fermi trigger No 677377371: Global MASTER-Net observations report
  20. Fermi GRB 220620B: Global MASTER-Net observations report
  21. Fermi GRB 220620A: Global MASTER-Net observations report
  22. GRB 220620B: Fermi GBM Final Real-time Localization
  23. Integral GRB220619.53: Global MASTER-Net observations report
  24. GRB 220619A: AstroSat CZTI detection
  25. Swift GRB220620.02: Global MASTER-Net observations report
  26. GRB 220620A: Fermi GBM Final Real-time Localization
  27. GRB 220611A: Continued Gemini Infrared Observations
  28. GRB 220617A: TNG optical observations
  29. Fermi trigger No 677307509: Global MASTER-Net observations report
  30. Fermi trigger No 677236224: Global MASTER-Net observations report
  31. GRB 220617A: Fermi GBM observation
  32. Swift Trigger 1110865 is probably not an astrophysical event
  33. GRB 220611A optical counterpart
  34. GRB 220618A: Swift-XRT refined Analysis
  35. IPN triangulation of GRB 220617A (short)
  36. GRB 220618A: BOOTES-5/JGT early optical upper limit
  37. GRB 220618A: Swift/UVOT Upper Limits
  38. GRB220611A: Gemini Optical Afterglow Confirmation
  39. GRB 220618A: Enhanced Swift-XRT position
  40. GRB 220617A: Swift-XRT observations
  41. GRB 220618A: Swift detection of a burst
  42. Swift GRB220618.38: Global MASTER-Net observations report
  43. GRB 220617A: Fermi-LAT detection
  44. GRB 220617B: Swift ToO observations
  45. Fermi GRB 220617A: Global MASTER-Net observations report
  46. GRB 220617A: Fermi GBM Final Real-time Localization
  47. GRB 220611A: Gemini Ks counterpart detection
  48. Fermi trigger No 677174940: Global MASTER-Net observations report
  49. Konus-Wind detection of GRB 220613A
  50. IPN triangulation of GRB 220613A
  51. Konus-Wind detection of an intermediate flare from SGR 1935+2154 on June 16
  52. GRB 220611A: Gemini South Infrared Detection
  53. IPN triangulation of GRB 220606C
  54. GRB 220611A: Swift/UVOT Upper Limits
  55. Fermi trigger No 676909037: Global MASTER-Net observations report
  56. GRB 220612A: CALET Gamma-Ray Burst Monitor detection
  57. GRB 220612A: Swift/BAT-GUANO detection
  58. GRB 220611A: Swift-BAT refined analysis
  59. GRB 220608B: Detection by VZLUSAT-2
  60. Swift GRB 220611A: Global MASTER-Net observations report
  61. GRB 220611A: Swift-XRT refined Analysis
  62. GRB 220610B: AstroSat CZTI detection
  63. GRB 220611A: Enhanced Swift-XRT position
  64. GRB 220611A: Swift detection of a burst
  65. IPN triangulation of GRB 220609B
  66. Fermi GRB 220610A: Global MASTER-Net observations report
  67. GRB 220610A: Fermi GBM Final Real-time Localization
  68. Fermi trigger No 676537486: Global MASTER-Net observations report
  69. GRB 220609B: AstroSat CZTI detection
  70. GRB 220609B: CALET Gamma-Ray Burst Monitor detection
  71. Fermi trigger No 676366592: Global MASTER-Net observations report
  72. GRB 220608A: AstroSat CZTI detection
  73. GRB 220609A: Fermi GBM Final Real-time Localization
  74. GRB 220606A: Fermi GBM observation
  75. GRB 220606C: CALET Gamma-Ray Burst Monitor detection
  76. Fermi GRB 220608A: Global MASTER-Net observations report
  77. GRB 220608A: Fermi GBM Final Real-time Localization
  78. GRB 220606B: Gemini South Optical Observations
  79. MAXI GRB220607.31: Global MASTER-Net observations report
  80. MAXI GRB220607.41: Global MASTER-Net observations report
  81. GRB 220606B: Fermi GBM Observation
  82. GRB 220606B: Swift follow-up observations
  83. Konus-Wind detection of GRB 220601A
  84. GRB 220606A: Swift/BAT-GUANO detection
  85. GRB 220606B: GUANO coordinate correction to GCN 32167
  86. GRB 220527A: A BdHN I with a clear UPE phase
  87. GRB 220606B: Swift ToO observations
  88. GRB 220606B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  89. Fermi GRB 220606B: Global MASTER-Net observations report
  90. GRB 220606B: Fermi GBM Final Real-time Localization
  91. GRB 220606A: Fermi GBM Final Real-time Localization
  92. IPN triangulation of GRB 220601A (long)
  93. Fermi trigger No 675992935: Global MASTER-Net observations report
  94. GRB 220603A: Swift/BAT-GUANO detection outside the coded FOV
  95. Fermi-GBM will trial new SAA regions from Tuesday June 7th
  96. GRB 220527A: MITSuME Akeno continued optical observation
  97. GRB 220527A: Lick 3m Optical Observations
  98. Konus-Wind detection of GRB 220528A
  99. IPN triangulation of GRB 220528A (short)
  100. GRB 220528A: Fermi GBM Observation

Advanced

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