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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"

19663 results found.

  1. GRB 230818A: AKO Upper Limit
  2. GRB 230818A: AstroSat CZTI detection
  3. GRB 230818A: Leavitt Observatory upper limit
  4. GRB 230818A: Swift-XRT refined Analysis
  5. GRB 230818A: Bassano Bresciano Observatory optical observations
  6. GRB 230818A: KGO RC-25 optical observations
  7. GRB 230818A: Swift/UVOT Detection
  8. GRB 230818A: NOT photometry and spectroscopy
  9. GRB 230818A: Enhanced Swift-XRT position
  10. GRB 230818A: Swift detection of a burst
  11. Swift GRB230818.98: Global MASTER-Net observations report
  12. Swift GRB230818.98: Global MASTER-Net OT detection
  13. GRB 230816A: Swift-BAT refined analysis
  14. GRB 230816A: SVOM/C-GFT optical detection
  15. GRB 230816A: Swift-XRT refined Analysis
  16. GRB 230816A: Osservatorio Astronomico "Nastro Verde" optical observations
  17. GRB 230816A: Enhanced Swift-XRT position
  18. GRB230816A: Possible host and GIT detection of optical counterpart
  19. Swift GRB230816.80: Global MASTER-Net observations report
  20. IPN triangulation of GRB 230815B
  21. GRB 230816A: Nanshan/HMT optical afterglow detection
  22. GRB 230815A: SOAR/Goodman follow-up imaging
  23. Swift GRB230816.67: Global MASTER-Net observations report
  24. GRB 230816A: Swift detection of a burst
  25. GRB 230815A: Swift-BAT refined analysis
  26. GRB230815A: Swift/UVOT upper limits
  27. GRB 230812B: GAD Observatory optical observations (upper limit)
  28. GRB 230815A: Swift-XRT refined Analysis
  29. GRB 230812B: iTelescope optical upper limit
  30. GRB230815A: BOOTES-6/DPRT optical upper limit
  31. GRB 230815A: Fermi GBM detection
  32. Swift GRB 230815A: Global MASTER-Net observations report
  33. GRB 230815A: Enhanced Swift-XRT position
  34. GRB 230815A: Swift detection of a burst
  35. GRB 230812B: Upper limits from a neutrino search with IceCube
  36. GRB 230812B: GIT optical follow-up
  37. GRB 230812B: Faulkes Telescope North optical afterglow follow-up
  38. GRB 230812B: Osservatorio Astronomico "Nastro Verde" optical observation
  39. GRB 230812B: OASDG optical observations
  40. GRB 230812B: Detected Optical Afterglow Candidate
  41. GRB230812B: AGILE/MCAL detection
  42. GRB 230812B: Swift-XRT afterglow detection
  43. GRB 230812: Swift/UVOT Detection
  44. GOTO confirmation and possible host galaxy of GRB230812B optical afterglow
  45. GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi GRB (Trigger 713559497)
  46. Fermi GRB 230812B: MASTER optical counterpart
  47. GRB 230812B: KAIT Optical Afterglow Candidate
  48. GRB 230812B: Improved Swift/XRT localization
  49. GRB 230812B: Preliminary Swift/XRT localization
  50. GRB 230812B: Tiled Swift observations
  51. GRB 230808A: Fermi GBM Detection
  52. GRB 230805B: Swift-BAT refined analysis
  53. GRB 230805B: Iota Scorpii Observatory, La Spezia, Italy upper limit
  54. GRB 230805B: AstroSat CZTI detection
  55. GRB 230808A: Swift/BAT-GUANO detection of a burst
  56. GRB 230805B : MITSuME Akeno optical upper limits
  57. LIGO/Virgo/KAGRA S230805x: Upper limits from Swift/BAT-GUANO
  58. GRB 230805B: Fermi GBM observation
  59. GRB 230805B: Enhanced Swift-XRT position
  60. GRB 230805B: Swift/UVOT Upper Limits
  61. GRB 230805B: Bassano Bresciano observatory upper limit
  62. GRB 230805B: BOOTES-6/DPRT optical upper limit and 1.5m OSN detection
  63. GRB 230805B: Swift-XRT refined Analysis
  64. Swift GRB 230805B: Global MASTER-Net observations report
  65. GRB 230805B: Swift detection of a burst
  66. GRB 230802A: Fermi GBM observation
  67. GRB 230802A: Swift-BAT refined analysis
  68. GRB 230802A: Swift/UVOT Upper Limits
  69. Swift GRB 230802A: Global MASTER-Net observations report
  70. GRB 230802A: BOOTES-5/JGT optical upper limit
  71. GRB 230802A: Swift-XRT refined Analysis
  72. GRB 230802A: Enhanced Swift-XRT position
  73. GRB 230802A: Swift detection of a burst
  74. LIGO/Virgo/KAGRA S230731an: Upper limits from Swift/BAT-GUANO
  75. GRB 230728A: Swift-BAT refined analysis
  76. GRB 230723B: Swift-BAT refined analysis
  77. GRB 230723B: MITSuME Ishigaki optical observation
  78. GRB 230728A: BOOTES-1 optical upper limit
  79. GRB 230728A: Fermi GBM Observation
  80. GRB 230728A: LCOGT Optical Upper Limit
  81. GRB 230728A: Swift/UVOT Upper Limits
  82. GRB 230728A: Swift-XRT refined Analysis
  83. GRB 230728A: Enhanced Swift-XRT position
  84. GRB 230728A: NOT optical observations and possible host galaxy
  85. GRB 230727A: AstroSat CZTI detection
  86. GRB 230728A: Swift detection of a burst
  87. Swift GRB230728.12: Global MASTER-Net observations report
  88. GRB 230727A: Swift/BAT-GUANO detection of a burst
  89. GRB 230723B: MITSuME Akeno optical afterglow candidate detection
  90. IBAS trigger number 10337: not a real GRB
  91. GRB 230723B: GAD Observatory, La Spezia, Italy upper limit
  92. GRB 230723B: Leavitt Observatory upper limit
  93. GRB 230723B: Osservatorio Astronomico Nastro Verde upper limit
  94. GRB 230723B: Montarrenti Observatory upper limit
  95. GRB 230723B: Bassano Bresciano Observatory upper limit
  96. GRB 230723B: Fermi GBM observation
  97. GRB 230723B: Swift-XRT refined Analysis
  98. GRB 230723B: Swift/UVOT Upper Limits
  99. Swift GRB 230723B: Global MASTER-Net observations report
  100. Swift-XRT position for GRB 230723B

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