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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"

20008 results found.

  1. GRB 230228A: Miryang Arirang Astronomical Observatory (MAAO) 0.7-m telescope optical upper limit
  2. GRB 230228A: Prompt enhanced Swift-XRT position
  3. GRB 230228A: Swift detection of a possibly short burst
  4. GRB 230216A Mondy Observations
  5. GRB 230217A: Swift/UVOT Upper Limits
  6. GRB 230216A: Swift/UVOT Upper Limits
  7. GRB 230217A: Swift-XRT afterglow detection
  8. GRB 230217A: Swift-BAT refined analysis
  9. GRB 230217A: AstroSat CZTI detection
  10. GRB 230217A: 6 GHz VLA observations
  11. GRB 230217A: Fermi GBM observation
  12. Konus-Wind detection of GRB 230217A
  13. GRB 230217A: Swift-XRT observations
  14. GRB 230217A: AGILE/MCAL detection
  15. GRB 230207B: CALET Gamma-Ray Burst Monitor detection
  16. GRB 230216A: SVOM/C-GFT optical upper limit
  17. GRB 230217A: Swift detection of a short burst
  18. GRB 230216A: Swift-BAT refined analysis
  19. GRB 230216A: Swift-XRT refined Analysis
  20. Swift GRB 230216A: Global MASTER-Net observations report
  21. GRB 230216A: Enhanced Swift-XRT position
  22. GRB 230216A: AKO Upper Limit
  23. GRB 230216A: Zadko observatory - Gingin optical observations
  24. GRB 230216A: Swift detection of a burst
  25. GRB 230209B: AGILE detection
  26. GRB 230209B: Fermi GBM Observation
  27. IPN triangulation of GRB 230209B
  28. GRB 230204B: CALET Gamma-Ray Burst Monitor detection
  29. GRB 230209B: Swift/BAT-GUANO detection outside the coded FOV
  30. Swift Trigger 1153670 is probably not a GRB
  31. GRB 221009A: Continued Swift Observations
  32. GRB 230207B: Detection by GRBAlpha
  33. GRB 230207B: Swift/BAT-GUANO detection outside the coded FOV
  34. ZTF23aabmzlp/AT2023azs: Neil Gehrels Swift Observatory X-ray observations
  35. GRB 230204B: Swift/UVOT Upper Limits
  36. GRB 230205A: Swift/UVOT Upper Limits
  37. GRB 230204B: Fermi GBM detection
  38. GRB 230204B: Swift-XRT afterglow detection
  39. GRB 230205A: SVOM/C-GFT optical upper limit
  40. GRB 230205A: Swift-BAT refined analysis (T90 = 2.3 s)
  41. GRB 230204A: Swift-BAT refined analysis
  42. GRB 230205A: Swift-XRT refined Analysis
  43. GRB 230204B: Swift ToO observations
  44. GRB 230205A: Enhanced Swift-XRT position
  45. GRB 230205A: BOOTES-5/JGT early optical upper limit
  46. GRB 230204B: Detection by GRBAlpha
  47. GRB 230204B: AGILE detection
  48. GRB 230205A: Swift detection of a burst
  49. GRB 230204B: GIT discovery of the likely optical afterglow
  50. GRB 230204B: AstroSat CZTI detection
  51. GRB 230204B: Swift/BAT-GUANO detection outside the coded FOV
  52. GRB 230204A: Swift/UVOT Upper Limits
  53. GRB 230204A: Swift-XRT refined Analysis
  54. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  55. GRB 230204A: Enhanced Swift-XRT position
  56. GRB 230204A: Swift detection of a possible burst (or possible transient Swift J1552.8-5055)
  57. GRB 221216A: Swift-BAT refined analysis
  58. AT2023avj: X-ray Detection with Swift/XRT
  59. Swift-XRT observations of NuEm-230125A
  60. Trigger 1150965: Swift detection of LS V +44 17
  61. GRB 230124A: Fermi GBM Observation
  62. GRB 230124A: Swift/BAT-GUANO detection outside the coded FOV
  63. GRB 230123A: Swift-BAT refined analysis
  64. GRB 230122A: Swift/BAT-GUANO detection
  65. GRB 230123A: Swift/UVOT Upper Limits
  66. GRB 230123A: Swift-XRT refined Analysis
  67. GRB 230123A: Enhanced Swift-XRT position
  68. GRB 230123A: Zadko observatory - Gingin optical observations
  69. GRB 230116C: Swift-XRT observations
  70. GRB 230123A: Swift detection of a burst
  71. Trigger 1150107: Swift detection of LS V +44 17
  72. GRB 230116D: 3.6m DOT optical upper limit
  73. GRB 230116D: Swift-BAT refined analysis
  74. GRB 230116C: Swift-BAT refined analysis
  75. GRB 230116D: Swift-XRT refined Analysis
  76. GRB 230116D: GIT optical follow-up
  77. GRB 230116D: Enhanced Swift-XRT position
  78. GRB 230116D: Nanshan/NEXT optical afterglow detection
  79. GRB 230116D: Swift detection of a burst
  80. Swift GRB230116.88: Global MASTER-Net observations report
  81. GRB 230116C: Swift detection of a burst
  82. Trigger 1148770: Swift detection of Cyg X-1 due to Star Tracker loss of lock
  83. GRB 230102A: Fermi GBM Observation
  84. GRB 221231A: 3.6m DOT optical upper limit
  85. GRB 230102A: Swift/BAT-GUANO detection outside the coded FOV
  86. GRB 221231A: Fermi GBM Observation
  87. GRB 221231A: Swift-XRT afterglow detection
  88. GRB 221231A: AKO Upper Limit
  89. GRB 221231A: Swift-XRT observations
  90. GRB 221231A: Swift ToO observations
  91. GRB 221231A: Swift/BAT-GUANO arcminute localization of a possibly short burst
  92. GRB 221226A: Fermi GBM detection
  93. IPN triangulation of GRB 221226A
  94. GRB 221226A: Swift/BAT-GUANO detection outside the coded FOV
  95. ZTF22acaruqr/AT2022adzb: Neil Gehrels Swift Observatory X-ray detection
  96. GRB 221226B Swift-BAT refined analysis
  97. GRB 221226B: Swift-UVOT Detection
  98. GRB 221226B: Fermi GBM Observation
  99. GRB 221226B: Swift-XRT refined Analysis
  100. GRB 221226B: VLT/X-shooter redshift and host galaxy

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