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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"

21468 results found.

  1. GRB231104A: LCOGT Optical Upper Limits
  2. GRB 231104A: Swift detection of a bright burst
  3. Swift GRB231104.07: Global MASTER-Net observations report
  4. New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
  5. IPN triangulation of GRB 231020A
  6. GRB 231028A: Swift-BAT refined analysis
  7. LIGO/Virgo/KAGRA S231029y: Upper limits from Swift/BAT-GUANO
  8. GRB 231028A: CALET Gamma-Ray Burst Monitor detection
  9. GRB 231028A: AstroSat CZTI detection
  10. GRB 231028A: Glowbug gamma-ray detection
  11. GRB 231028A: Fermi GBM Detection
  12. Swift GRB 231028A: Global MASTER-Net observations report
  13. GRB 231028A: Swift detection of a burst
  14. GRB 231025A: Fermi GBM Observation
  15. GRB 231025A: Swift/BAT-GUANO detection of a likely short burst
  16. GRB 231018A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  17. LIGO/Virgo/KAGRA S231020bw: Upper limits from Swift/BAT-GUANO
  18. GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
  19. GRB 231017A: 1.3m DFOT Optical upper limit
  20. GRB 231018A: Glowbug gamma-ray detection
  21. IPN triangulation of GRB 231018A
  22. GRB 231017A: Swift/UVOT Upper Limit
  23. GRB 230911C: ATCA detection of possible radio counterpart
  24. GRB 231017A: GOTO optical upper limits
  25. GRB 231017A: JinShan optical upper limit
  26. GRB 231017A: Las Cumbres optical upper limit
  27. GRB 231017A: LCOGT Optical Upper Limits
  28. GRB231017A: GROWTH-India upper limits on the optical afterglow
  29. GRB 231017A: Fermi GBM Detection
  30. GRB 231017A: Swift-XRT observations
  31. GRB 231017A: Swift ToO observations
  32. GRB 231017A: Swift/BAT-GUANO candidate arcminute localization of a burst
  33. LIGO/Virgo/KAGRA S231014r: Upper limits from Swift/BAT-GUANO
  34. LIGO/Virgo/KAGRA S231005j: Upper limits from Swift/BAT-GUANO
  35. LIGO/Virgo/KAGRA S231001aq: Upper limits from Swift/BAT-GUANO
  36. LIGO/Virgo/KAGRA S230930al: Upper limits from Swift/BAT-GUANO
  37. LIGO/Virgo/KAGRA S230928cb: Upper limits from Swift/BAT-GUANO
  38. NuEm-230927A: Swift-XRT follow-up
  39. Swift Triggers 1192745 and 1192747 are not astrophysical events
  40. Swift Triggers 1192740, 1192742 and 1192743 are not astrophysical events
  41. Swift Triggers 1192735 and 1192737 are not astrophysical events
  42. Konus-Wind detection of GRB 230919A
  43. LIGO/Virgo/KAGRA S230924an: Upper limits from Swift/BAT-GUANO
  44. LIGO/Virgo/KAGRA S230920al: Upper limits from Swift/BAT-GUANO
  45. LIGO/Virgo/KAGRA S230919bj: Upper limits from Swift/BAT-GUANO
  46. LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
  47. LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
  48. IPN triangulation of GRB 230919A (short)
  49. GRB 230919A: Fermi GBM Observation
  50. GRB 230919A: Swift/BAT-GUANO detection of a possibly short burst outside the coded FOV
  51. LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
  52. GRB 230915A: Fermi GBM observation
  53. Swift Triggers 1192480, 1192481, 1192482 and 1192483 are not astrophysical events
  54. GRB 230911A: Fermi GBM Observation
  55. Swift GRB230916.18: Global MASTER-Net observations report
  56. GRB 230915A: Swift/BAT-GUANO detection of a burst
  57. LIGO/Virgo/KAGRA S230914ak: Upper limits from Swift/BAT-GUANO
  58. Swift GRB230916.19: Global MASTER-Net observations report
  59. Swift GRB230916.18: Global MASTER-Net observations report
  60. Swift Triggers 1192234, 1192235 and 1192236 are not astrophysical events
  61. Swift GRB230916.13: Global MASTER-Net observations report
  62. Swift GRB230916.12: Global MASTER-Net observations report
  63. Swift GRB230916.11: Global MASTER-Net observations report
  64. Swift Trigger 1192233 is not a GRB
  65. GRB 230911A: Swift-XRT afterglow detection
  66. GRB 230913A: CALET Gamma-Ray Burst Monitor detection
  67. Swift Trigger 1192088 is not an astrophysical event
  68. GRB 230913A: Glowbug gamma-ray detection
  69. Swift Trigger 1191994 is not an astrophysical event
  70. Swift GRB230913.70: Global MASTER-Net observations report
  71. GRB 230913A: Fermi GBM Observation
  72. Swift Trigger 1191904 is not a GRB
  73. Swift GRB230913.70: Global MASTER-Net observations report
  74. Swift Trigger 1191903 is not an astrophysical event
  75. GRB 230911A: Swift ToO observations
  76. GRB 230913A: Swift/BAT-GUANO arcminute localization of a burst
  77. GRB 230908A: CALET Gamma-Ray Burst Monitor detection
  78. GRB 230911C: Swift-XRT refined Analysis
  79. GRB 230911C: Swift-BAT refined analysis
  80. GRB230911C: BOOTES-6/DPRT optical upper limit
  81. GRB 230906A: Chandra detection of the X-ray afterglow
  82. Swift GRB 230911C: Global MASTER-Net observations report
  83. IPN triangulation of GRB 230911D (long)
  84. GRB 230911D: Fermi-LAT detection
  85. GRB230911C: LCOGT Optical Upper Limits
  86. GRB 230911C: Swift/UVOT Upper Limits
  87. GRB 230911C: GOTO optical upper limits
  88. GRB 230908A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  89. GRB 230911C: Enhanced Swift-XRT position
  90. GRB 230911C: Swift detection of a burst
  91. GRB 230906A: BlackGEM upper limits
  92. GRB 230903A: TESS observations of optical emission
  93. GRB 230906A: Swift/UVOT Upper Limits
  94. GRID detection of GRB 230827A
  95. GRB 230906A: Swift-XRT observations
  96. IPN triangulation of GRB 230906A (short)
  97. GRB 230906A: Swift ToO observations
  98. Swift Attitude Control Affecting Some UVOT Images
  99. GRB 230812B: Chandra late-time detection of the X-ray afterglow
  100. GRB 230903A: Swift-XRT refined Analysis

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