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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"

26119 results found.

  1. GRB 211229A: Fermi GBM observation
  2. GRB 211229C: Swift/BAT-GUANO detection likely outside the coded FOV
  3. GRB 211229A: Swift ToO observations
  4. GRB 211229A: Swift/BAT-GUANO arcminute localization
  5. GRB 211227A: CALET Gamma-Ray Burst Monitor detection
  6. GRB 211225B: CALET Gamma-Ray Burst Monitor detection
  7. GRB 211227A: Swift/UVOT Upper Limits
  8. GRB 211227A: Swift-XRT refined Analysis
  9. GRB 211227A: Swift-BAT refined analysis
  10. Konus-Wind detection of the intermediate flare from SGR 1935+2154
  11. GRB 211227A: A possible short GRB with extended emission at z = 0.228?
  12. GRB 211227A: Liverpool Telescope upper limits
  13. GRB 211227A: Enhanced Swift-XRT position
  14. GRB 211227A: LCO Optical Observations
  15. GRB 211227A: Nanshan/NEXT optical observations and host galaxy candidate
  16. GRB 211227A: MAXI/GSC detection
  17. GRB 211227A: BOOTES-2/TELMA optical upper limit
  18. GRB 211221A: Swift/UVOT Upper Limits
  19. GRB 211227A: Swift detection of a burst
  20. Swift GRB211227.98: Global MASTER-Net observations report
  21. GRB 211226A: Swift/BAT-GUANO detection outside the coded FOV
  22. GRB 211225B: Swift-BAT refined analysis
  23. Swift GRB 211225B: Global MASTER-Net observations report
  24. GRB 211225B: Swift detection of a burst
  25. GRB 211211A: observations with the 3.6m Devasthal Optical Telescope
  26. GRB 211223C: Swift-BAT refined analysis
  27. GRB 211223C: BOOTES-4/MET optical upper limit
  28. Swift GRB 211223C: Global MASTER-Net observations report
  29. Fermi GBM Sub-Threshold Detection of GRB 211221A
  30. Fermi GBM Sub-Threshold Detection of GRB 211207A
  31. GRB 211221A: Swift-BAT refined analysis
  32. GRB 211223C: Swift detection of a burst
  33. GRB 211221A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  34. GRB 211219A: AstroSat CZTI detection
  35. GRB 211221A: Swift-XRT refined Analysis
  36. GRB 211221A: BOOTES-4/MET optical upper limit
  37. GRB 211221A: MeerLICHT optical limits
  38. GRB 211221A: NOT optical limits
  39. GRB 211221A: Enhanced Swift-XRT position
  40. Swift GRB 211221A: Global MASTER-Net observations report
  41. GRB 211221A: Swift detection of a burst
  42. GRB 211219A: Swift/BAT-GUANO detection outside the coded FOV
  43. GRB 211211A: MMT/MMIRS Observations Indicate Fading of K-band Source
  44. GRB 211216A: Fermi GBM observation
  45. GRB 211106A: XMM-Newton monitoring campaign detections
  46. GRB 211216A: Swift/BAT-GUANO detection outside the coded FOV
  47. GRB 211211A: Insight-HXMT/HE detection
  48. GRB 211211A - Gemini K-band detection
  49. GRB 211211A: SAO RAS optical observations
  50. GRB 211211A: AbAO optical observations
  51. GRB 211211A: GMG upper limit
  52. GRB 211211A: Very fast decay observed from CAFOS/2.2mCAHA
  53. GRB 211211A: Further observations from CAFOS/2.2m CAHA
  54. GRB 211211A: HCT and GIT optical follow up observations
  55. GRB 211211A: CALET Gamma-Ray Burst Monitor detection
  56. GRB 211211A: Swift/UVOT detection
  57. GRB 211211A: NOT optical spectroscopy
  58. GRB 211211A: Afterglow detection from CAFOS/2.2m CAHA
  59. GRB 211211A: MITSuME Akeno optical observation
  60. Swift GRB 211211A: Global MASTER-Net observations report
  61. GRB 211211A: LCO Optical Observations
  62. GRB 211211A: Nanshan/NEXT optical observations
  63. GRB 211211A: Swift-XRT refined Analysis
  64. GRB 211211A: Fermi GBM observation
  65. GRB 211211A: Swift-BAT refined analysis
  66. GRB 211211A: Enhanced Swift-XRT position
  67. GRB 211207A: Swift/UVOT Detection
  68. GRB 211211A: KAIT Optical Afterglow Candidate
  69. GRB 211211A: Swift detection of a bright burst
  70. GRB 211130A: MeerLICHT identification of possible afterglow candidate
  71. GRB 211207A: Swift-BAT refined analysis
  72. GRB 211207A: VLT/X-shooter redshift
  73. Chandra observation of GW170817 at ~1573 days since merger (Epoch 1 of 4)
  74. GRB 211204C: Fermi GBM detection
  75. GRB 211207A: Swift-XRT refined Analysis
  76. GRB 211207A: Enhanced Swift-XRT position
  77. Swift GRB 211207A: Global MASTER-Net observations report
  78. GRB 211207A: Swift detection of a burst with an optical counterpart
  79. GRB 211206A: AstroSat CZTI detection
  80. GRB 211204C: AstroSat CZTI detection
  81. IPN triangulation of GRB 211204C
  82. GRB 211206A: Swift/BAT-GUANO detection outside the coded FOV
  83. GRB 211204C: Swift/BAT-GUANO detection outside the coded FOV
  84. GRB 211124A: Fermi GBM Observation
  85. Swift Trigger 1086826 (possible GRB 211203A) is likely not an astrophysical event
  86. Swift GRB 211203A: Global MASTER-Net observations report
  87. Fermi GBM Upper limits for GRB 211203A
  88. GRB 211203A: Swift detection of a burst
  89. GRB 211201A: Swift/BAT-GUANO detection likely outside the coded FOV
  90. GRB 211106A: Second HST Observation
  91. GRB 211106A: GECAM detection
  92. GRB 211129A: Swift-BAT refined analysis
  93. GRB 211129A: Swift-XRT refined Analysis
  94. GRB 211129A: Swift/UVOT Upper Limits
  95. GRB 211106A: HST Observations
  96. GRB 211106A: Chandra Observations
  97. GRB 211129A: Fermi GBM observation
  98. Swift GRB 211129A: Global MASTER-Net observations report
  99. GRB 211129A: Nanshan/NEXT optical upper limit
  100. GRB 211129A: Enhanced Swift-XRT position

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