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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"

26121 results found.

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

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