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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

36380 results found.

  1. GRB 230228A: Swift detection of a possibly short burst
  2. Fermi GRB 230227A: Global MASTER-Net observations report
  3. GRB 230227A: Fermi GBM Final Real-time Localization
  4. GRB 230217A: VLT/FORS2 optical observations and candidate counterpart
  5. GRB 230216A Mondy Observations
  6. GRB 230205A: VLA radio afterglow confirmation
  7. GRB 230217A: Swift/UVOT Upper Limits
  8. GRB 230216A: Swift/UVOT Upper Limits
  9. GRB 230217A: Continued Gemini Observations
  10. GRB 230220A: Correction to GCN 33352
  11. GRB 230222A: Fermi GBM Final Real-time Localization
  12. GRB 230217A: Swift-XRT afterglow detection
  13. GRB 230217A: Swift-BAT refined analysis
  14. Fermi GRB 230220B: Global MASTER-Net observations report
  15. GRB 230217A: AstroSat CZTI detection
  16. GRB 230217A: Gemini South optical upper limits
  17. GRB 230216B: CALET Gamma-Ray Burst Monitor detection
  18. GRB 230217A: 6 GHz VLA observations
  19. GRB 230220B: Fermi GBM Final Real-time Localization
  20. GRB 230217A: Gemini-South Optical Observation
  21. GRB 230217A: Fermi GBM observation
  22. GRB 230220A: MAXI/GSC detection
  23. Konus-Wind detection of GRB 230217A
  24. GRB 230217A: Swift-XRT observations
  25. GRB 230218A is not a GRB
  26. GRB 230218A: Fermi GBM Final Real-time Localization
  27. GRB 230217A: AGILE/MCAL detection
  28. GRB 230207B: CALET Gamma-Ray Burst Monitor detection
  29. GRB 230216B: AstroSat CZTI detection
  30. GRB 230216A: SVOM/C-GFT optical upper limit
  31. GRB 230217A: Swift detection of a short burst
  32. GRB 230217A: Fermi GBM Final Real-time Localization
  33. GRB 230216A: Swift-BAT refined analysis
  34. GRB 230216A: Swift-XRT refined Analysis
  35. GRB 230205A: Lowell Discovery Telescope Observations
  36. GRB 230204B: Lowell Discovery Telescope Observations
  37. Swift GRB 230216A: Global MASTER-Net observations report
  38. GRB 230216A: Enhanced Swift-XRT position
  39. GRB 230216A: AKO Upper Limit
  40. GRB 230216A: Zadko observatory - Gingin optical observations
  41. GRB 230216A: Swift detection of a burst
  42. Fermi GRB 230215A: Global MASTER-Net observations report
  43. GRB 230215A: Fermi GBM Final Real-time Localization
  44. GRB 230209B: AGILE detection
  45. GRB 230209B: Fermi GBM Observation
  46. IPN triangulation of GRB 230209B
  47. GRB 230204B: CALET Gamma-Ray Burst Monitor detection
  48. GRB 230204B: ATCA radio detection
  49. 230211A is not a GRB
  50. GRB 230211A: Fermi GBM Final Real-time Localization
  51. GRB 230209B: Swift/BAT-GUANO detection outside the coded FOV
  52. Swift Trigger 1153670 is probably not a GRB
  53. GRB 230210A: Fermi GBM Final Real-time Localization
  54. Fermi GRB 230209B: Global MASTER-Net observations report
  55. GRB 230209B: Fermi GBM Final Real-time Localization
  56. GRB 230205A: 6 GHz VLA observations
  57. GRB 230209A is not a GRB
  58. GRB 230205A: SUBARU HSC pre-imaging for host galaxy search
  59. GRB 230209A: Fermi GBM Final Real-time Localization
  60. GRB 221009A: Continued Swift Observations
  61. Fermi Gamma-ray Burst Monitor trigger 230208382/697540213 is not a GRB
  62. GRB 230207B: Detection by GRBAlpha
  63. GRB 230205A: possible host galaxy detection with the Schmidt - Asiago telescope
  64. GRB 230204B: MASTER early OT detection
  65. GRB 230208A: Fermi GBM Final Real-time Localization
  66. Fermi Gamma-ray Burst Monitor triggers 230206723/697396830 and 230206797/697403223 are not GRBs
  67. GRB 230207B: Swift/BAT-GUANO detection outside the coded FOV
  68. GRB 230207B: AGILE detection of a burst
  69. Fermi GRB 230207A: Global MASTER-Net observations report
  70. GRB 230207A: Fermi GBM Final Real-time Localization
  71. GRB 230204B: LCOGT Optical Upper Limits
  72. GRB 230204B: Swift/UVOT Upper Limits
  73. GRB 230205A: Swift/UVOT Upper Limits
  74. GRB 230204B: Fermi GBM detection
  75. GRB 230205A: LCOGT Optical Upper Limits
  76. GRB 230204B: Swift-XRT afterglow detection
  77. GRB 230204B: 3.6m DOT optical observation
  78. GRB 230205A: SVOM/C-GFT optical upper limit
  79. GRB 230205A: OHP/T193 optical observations
  80. GRB 230204B: VLT/X-shooter redshift
  81. GRB 230205A: Swift-BAT refined analysis (T90 = 2.3 s)
  82. GRB 230204A: Swift-BAT refined analysis
  83. GRB 230204B: ATLAS detection of the optical afterglow and a projected location in a nearby galaxy group
  84. GRB 230205A: Swift-XRT refined Analysis
  85. GRB 230204B: Swift ToO observations
  86. GRB 230205A: Enhanced Swift-XRT position
  87. GRB 230205A: BOOTES-5/JGT early optical upper limit
  88. GRB 230204B: Detection by GRBAlpha
  89. GRB 230204B: AGILE detection
  90. GRB 230205A: Swift detection of a burst
  91. GRB 230204B: GIT discovery of the likely optical afterglow
  92. GRB 230204B: AstroSat CZTI detection
  93. GRB 230204B: Swift/BAT-GUANO detection outside the coded FOV
  94. GRB 230204A: Swift/UVOT Upper Limits
  95. GRB 230204B: MAXI/GSC detection
  96. GRB 230204A: Swift-XRT refined Analysis
  97. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  98. GRB 230204A: Enhanced Swift-XRT position
  99. GRB 230204A: Swift detection of a possible burst (or possible transient Swift J1552.8-5055)
  100. GRB 230201B: TURBO Optical Upper Limits

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