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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"

35958 results found.

  1. GRB 220624A: Fermi GBM Final Real-time Localization
  2. GRB 220623A: AbAO optical upper limit
  3. GRB 220623A: Swift-XRT refined Analysis
  4. GRB 220623A: NOT optical observations
  5. GRB 220623A: Swift/UVOT Upper Limits
  6. GRB 220623A: BOOTES-5/JGT optical afterglow detection
  7. Konus-Wind detection of GRB 220609B
  8. GRB 220623B: Fermi GBM Final Real-time Localization
  9. GRB 220623A: Enhanced Swift-XRT position
  10. GRB 220623A: AGILE detection
  11. GRB 220623A: AstroSat CZTI detection
  12. GRB 220623A: iTelescope optical upper limit
  13. GRB 220623A: Swift-XRT observations
  14. GRB 220623A: Swift detection of a burst
  15. GRB 220618A: Fermi GBM detection
  16. GRB 220618A: Swift-BAT refined analysis
  17. GRB 220618A: iTelescope T-19 upper limit
  18. Konus-Wind detection of GRB 220617A
  19. Fermi GRB 220620B: Global MASTER-Net observations report
  20. Fermi GRB 220620A: Global MASTER-Net observations report
  21. GRB 220620B: Fermi GBM Final Real-time Localization
  22. GRB 220619A: AstroSat CZTI detection
  23. GRB 220620A: Fermi GBM Final Real-time Localization
  24. GRB 220611A: Continued Gemini Infrared Observations
  25. GRB 220617A: TNG optical observations
  26. GRB 220617A: Fermi GBM observation
  27. GRB 220611A optical counterpart
  28. GRB 220618A: Swift-XRT refined Analysis
  29. IPN triangulation of GRB 220617A (short)
  30. GRB 220618A: BOOTES-5/JGT early optical upper limit
  31. GRB 220618A: Swift/UVOT Upper Limits
  32. GRB220611A: Gemini Optical Afterglow Confirmation
  33. GRB 220618A: Enhanced Swift-XRT position
  34. GRB 220617A: Swift-XRT observations
  35. GRB 220618A: Swift detection of a burst
  36. GRB 220617A: Fermi-LAT detection
  37. GRB 220617B: Swift ToO observations
  38. Fermi GRB 220617A: Global MASTER-Net observations report
  39. GRB 220617A: Fermi GBM Final Real-time Localization
  40. GRB 220611A: Gemini Ks counterpart detection
  41. Konus-Wind detection of GRB 220613A
  42. IPN triangulation of GRB 220613A
  43. GRB 220611A: Gemini South Infrared Detection
  44. IPN triangulation of GRB 220606C
  45. GRB 220611A: Swift/UVOT Upper Limits
  46. GRB 220612A: CALET Gamma-Ray Burst Monitor detection
  47. GRB 220612A: Swift/BAT-GUANO detection
  48. GRB 220611A: Swift-BAT refined analysis
  49. GRB 220608B: Detection by VZLUSAT-2
  50. Swift GRB 220611A: Global MASTER-Net observations report
  51. GRB 220611A: Swift-XRT refined Analysis
  52. GRB 220610B: AstroSat CZTI detection
  53. GRB 220611A: Enhanced Swift-XRT position
  54. GRB 220611A: Swift detection of a burst
  55. IPN triangulation of GRB 220609B
  56. Fermi GRB 220610A: Global MASTER-Net observations report
  57. GRB 220610A: Fermi GBM Final Real-time Localization
  58. GRB 220609B: AstroSat CZTI detection
  59. GRB 220609B: CALET Gamma-Ray Burst Monitor detection
  60. GRB 220608A: AstroSat CZTI detection
  61. GRB 220609A: Fermi GBM Final Real-time Localization
  62. GRB 220606A: Fermi GBM observation
  63. GRB 220606C: CALET Gamma-Ray Burst Monitor detection
  64. Fermi GRB 220608A: Global MASTER-Net observations report
  65. GRB 220608A: Fermi GBM Final Real-time Localization
  66. GRB 220606B: Gemini South Optical Observations
  67. GRB 220606B: Fermi GBM Observation
  68. GRB 220606B: Swift follow-up observations
  69. Konus-Wind detection of GRB 220601A
  70. GRB 220606A: Swift/BAT-GUANO detection
  71. GRB 220606B: GUANO coordinate correction to GCN 32167
  72. GRB 220527A: A BdHN I with a clear UPE phase
  73. GRB 220606B: Swift ToO observations
  74. GRB 220606B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  75. Fermi GRB 220606B: Global MASTER-Net observations report
  76. GRB 220606B: Fermi GBM Final Real-time Localization
  77. GRB 220606A: Fermi GBM Final Real-time Localization
  78. IPN triangulation of GRB 220601A (long)
  79. GRB 220603A: Swift/BAT-GUANO detection outside the coded FOV
  80. GRB 220527A: MITSuME Akeno continued optical observation
  81. GRB 220527A: Lick 3m Optical Observations
  82. Konus-Wind detection of GRB 220528A
  83. IPN triangulation of GRB 220528A (short)
  84. GRB 220528A: Fermi GBM Observation
  85. Fermi GRB 220530A: Global MASTER-Net observations report
  86. Konus-Wind observation of GRB 220527A
  87. GRB 220530A: Fermi GBM Final Real-time Localization
  88. Correction to GCN 32148: Should be GRB 220528A
  89. GRB 220528B: Swift/BAT-GUANO detection outside the coded FOV
  90. GRB 220528A: Fermi GBM Final Localization
  91. GRB 220527A: AST3-3 Yaoan Optical Observation
  92. GRB 220527A: REM optical/NIR observations
  93. GRB 220527A: VLT/X-shooter spectroscopic redshift
  94. GRB 220527A: MeerLICHT afterglow observations
  95. GRB 220527A: NOT optical photometry and spectroscopic redshift
  96. GRB 220527A: AstroSat CZTI detection
  97. GRB 220527A: CALET Gamma-Ray Burst Monitor detection
  98. GRB 220527A: MITSuME Akeno optical observation
  99. GRB 220527A: Swift/UVOT detection
  100. GRB 220527A: Swift-XRT afterglow detection

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