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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 220710A: Swift-XRT afterglow detection
  2. GRB 220711C: Swift/BAT-GUANO detection outside the coded FOV
  3. GRB 220711B, GROND observations
  4. Konus-Wind detection of GRB 220711C
  5. GRB 220711B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  6. GRB 220711B: GIT optical upper limits
  7. Fermi GRB 220711B: Global MASTER-Net observations report
  8. GRB 220712B: NOT optical afterglow confirmation
  9. GRB 220710A: Swift ToO observations
  10. GRB 220710A: Swift/BAT-GUANO arcminute localization
  11. GRB 220711B: Swift-BAT refined analysis
  12. IPN triangulation of GRB 220711C (short)
  13. GRB 220711B: Swift-XRT refined Analysis
  14. GRB 220711B: Swift/UVOT Upper Limits
  15. GRB 220711B: Enhanced Swift-XRT position
  16. GRB 220711B: Fermi GBM Detection
  17. GRB 220711B: NOT optical observations
  18. GRB 220711B: LCO Optical Upper Limits
  19. GRB 220711B: Swift detection of a burst
  20. GRB 220711B: Fermi GBM Final Real-time Localization
  21. GRB 220707A: AstroSat CZTI detection
  22. GRB 220708B: GIT optical upper limits
  23. GRB 220711A: Fermi GBM Final Real-time Localization
  24. GRB 220708A: Swift-BAT refined analysis
  25. GRB 220708B: T193-OHP optical upper limit
  26. Konus-Wind detection of GRB 220708B (Correction to GCN 32358)
  27. Konus-Wind detection of GRB 220708B
  28. GRB 220708B: CALET Gamma-Ray Burst Monitor detection
  29. GRB 220708B: Nanshan/NEXT optical upper limits
  30. GRB 220708A: Swift/UVOT Upper Limits
  31. GRB 220706A : NICER detection of re-brightening 1 day after the Swift trigger
  32. GRB 220708A: Swift-XRT refined Analysis
  33. GRB 220706A: Swift/UVOT Upper Limits
  34. GRB 220708B: Swift-XRT afterglow detection
  35. GRB 220708A: BOOTES-5/JGT early optical upper limit
  36. GRB 220706A: Swift-BAT refined analysis
  37. GRB 220708A: Enhanced Swift-XRT position
  38. GRB 220708B: Swift ToO observations
  39. GRB 220708B: Swift/BAT-GUANO arcminute localization
  40. GRB 220708A: Swift-XRT observations
  41. GRB 220708A: Swift detection of a burst
  42. GRB 220706A: LCO Optical Upper Limits
  43. GRB 220627A: ATCA detection of radio counterpart
  44. GRB 220706A: Swift-XRT refined Analysis
  45. GRB 220706A, GROND observations
  46. GRB 220706A: Optical observations from NOT
  47. GRB 220706A: MAXI/GSC detection 84 minutes after the Swift Trigger
  48. GRB 220702B: AstroSat CZTI detection
  49. GRB 220706A: Nanshan/NEXT optical upper limits
  50. GRB 220706A: Enhanced Swift-XRT position
  51. Swift GRB 220706A: Global MASTER-Net observations report
  52. GRB 220706A: Zadko observatory - Gingin optical observations
  53. GRB 220706A: Prompt enhanced Swift-XRT position
  54. GRB 220706A: Swift detection of a burst
  55. GRB 220701A: Swift-BAT refined analysis
  56. GRB 220702B: Fermi GBM Final Localization
  57. GRB 220702A: Fermi GBM Final Localization
  58. GRB 220705A: Fermi GBM Final Localization
  59. GRB 220701A: MITSuME Akeno optical upper limits
  60. GRB 220701A: COATLI Optical Upper Limit
  61. GRB 220701A: AbAO optical upper limit
  62. GRB 220627A: AstroSat CZTI detection
  63. GRB 220701A: Keck/LRIS Optical Upper Limit
  64. GRB 220701A: Swift-XRT refined Analysis
  65. GRB 220701A: LCO Optical Upper Limits
  66. GRB 220701A: BOOTES-5/JGT early optical upper limit
  67. GRB 220701A: Swift/UVOT Upper Limits
  68. GRB 220701A: Lowell Discovery Telescope Optical Observations
  69. GRB 220701A: Enhanced Swift-XRT position
  70. GRB 200701A: KAIT Optical Upper Limit
  71. GRB 220701A: Swift detection of a burst
  72. GRB 220627A, GROND observations
  73. GRB 220624A: AGILE/GRID refined analysis
  74. GRB 220627A: Swift/UVOT Upper Limits
  75. GRB 220627A: Swift-XRT afterglow detection
  76. Konus-Wind detection of GRB 220627A
  77. GRB 220627A: VLT MUSE redshift
  78. GRB 220627A: MeerLICHT candidate optical afterglow
  79. GRB 220627A: Fermi GBM Detection of a possible Lensed or Ultra-long GRB
  80. GRB 220627A: Swift/BAT-GUANO detection outside the coded FOV
  81. Konus-Wind detection of GRB 220624A
  82. GRB 220627A: Swift ToO observations
  83. GRB 220627A: Fermi-LAT detection
  84. GRB 220627A: MeerLICHT detection of two afterglow candidates
  85. Fermi GRB 220627A: Global MASTER-Net observations report
  86. GRB 220627A: Fermi GBM Final Real-time Localization
  87. GRB 220623A: GIT optical upper limits.
  88. GRB 220624A: CALET Gamma-Ray Burst Monitor detection
  89. GRB 220623A: T193-OHP optical upper limit
  90. GRB 220624A: Fermi GBM Detection
  91. Fermi GRB 220623B: Global MASTER-Net observations report
  92. Fermi GRB 220624A: Global MASTER-Net observations report
  93. IPN triangulation of GRB 220624A
  94. GRB 220623A: Swift-BAT refined analysis
  95. GRB 220624A: Swift/BAT-GUANO detection outside the coded FOV
  96. GRB 220611A: X-ray afterglow Chandra sub-arcsecond localization
  97. GRB 220624A: AGILE/GRID analysis
  98. GRB 220624A: AGILE detection
  99. Konus-Wind detection of GRB 220623A
  100. GRB 220624B: Fermi GBM Final Real-time Localization

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