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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"

19670 results found.

  1. GRB 201221D: Swift/UVOT Upper Limits
  2. GRB 201221D: Lowell Discovery Telescope afterglow observations
  3. GRB 201221D: FRAM-ORM optical limit
  4. GRB 201221D: Swift-XRT refined Analysis
  5. Swift GRB 201221D: Global MASTER-Net observations report
  6. GRB 201221D: Enhanced Swift-XRT position
  7. GRB 201221A: Swift-BAT refined analysis
  8. GRB 201221D: Prompt enhanced Swift-XRT position
  9. GRB 201221D: Swift detection of a bright short burst
  10. correction to GCN 29110 - Fermi GBM Sub-Threshold Detection of GRB 201221A
  11. Fermi GBM Sub-Threshold Detection of GRB 201221A
  12. GRB 201221A: Swift/UVOT Upper Limits
  13. GRB 201221A: Swift-XRT refined Analysis
  14. GRB 201221C: MASTER optical observtion
  15. Swift Trigger 1014012: possible GRB 201221C
  16. GRB 201221A: Enhanced Swift-XRT position
  17. GRB 201221A: FRAM-Auger optical limit
  18. Swift GRB 201221A: Global MASTER-Net observations report
  19. GRB 201221A: Prompt enhanced Swift-XRT position
  20. GRB 201221A: Swift detection of a burst
  21. GRB 201214A: Swift-XRT afterglow detection
  22. GRB 201214A: 1.3m DFOT, optical upper limits
  23. IPN triangulation of GRB 201218A
  24. GRB201216C: No significant detection in HAWC
  25. GRB 201216C: Liverpool Telescope First Hour Observations
  26. Konus-Wind detection of GRB 201216C
  27. GRB 201216C: Swift-BAT refined analysis
  28. GRB 201216C: Fermi-LAT upper limit
  29. GRB 201216C: MAGIC detection in very high energy gamma rays
  30. GRB 201216C: AstroSat CZTI detection
  31. GRB 201216C: Fermi GBM detection
  32. GRB 201216A: Fermi GBM detection
  33. GRB 201216C: Swift/UVOT Upper Limits
  34. GRB 201216A: Swift-XRT observations
  35. GRB 201216C: Enhanced Swift-XRT position
  36. GRB 201216C: VLT afterglow candidate discovery
  37. GRB 201216A: Swift ToO observations
  38. GRB 201216C: Swift-XRT observations
  39. Swift GRB201216.96: Global MASTER-Net observations report
  40. GRB 201216C: Swift detection of a burst
  41. GRB 201216A: Swift/BAT-GUANO detection and arcminute localization
  42. GRB 201214B: MITSuME Akeno optical upper limits
  43. GRB 201214B: Lowell Discovery Telescope optical observations
  44. GRB 201214B: Swift-XRT observations
  45. GRB 201209A: Insight-HXMT/HE detection
  46. GRB 201214A: Swift-XRT observations
  47. GRB 201214B: Swift BAT location of short burst
  48. GRB 201214B: Swift ToO observations
  49. GRB 201214A: Swift ToO observations
  50. GRB 201203A: 1.3m DFOT, optical upper limits
  51. GRB 201209A: Swift/UVOT Upper Limits
  52. GRB 201209A: Swift-BAT refined analysis
  53. GRB 201208A: Swift-XRT afterglow detection
  54. GRB 201209A: Swift-XRT refined Analysis
  55. GRB 201209A: AstroSat CZTI detection
  56. GRB 201209A: Enhanced Swift-XRT position
  57. IceCube-201130A: Optical and NIR Imaging Follow-up by Kanata Telescope
  58. GRB 201209A: KAIT Optical Upper Limit
  59. GRB 201209A: FRAM-Auger optical limit
  60. GRB 201209A: Swift detection of a burst
  61. Swift GRB201209.24: Global MASTER-Net observations report
  62. GRB 201208A: Fermi-LAT detection
  63. GRB 201208A: Swift ToO observations
  64. GRB 201203A: Swift-BAT refined analysis
  65. Swift follow-up observations of the flat spectrum radio quasar PMN J0206-1150 in the error region of IceCube-201130A
  66. GRB 201203A: GROWTH-India Telescope optical upper limit.
  67. GRB 201203A: MITSuME Okayama optical upper limits
  68. Swift GRB 201203A: Global MASTER-Net observations report
  69. GRB 201203A: Swift-XRT afterglow detection
  70. GRB 201203A: KAIT Optical Upper Limit
  71. GRB 201203A: DDOTI Observations
  72. GRB 201203A: FRAM-Auger optical limit
  73. GRB 201203A: Swift detection of a burst
  74. GRB 201128B: Swift-XRT observations
  75. Swift observations of the Fermi-LAT source 4FGL J0206.4-1151 in the error region of IceCube-201130A
  76. GRB 201128B: Swift ToO observations
  77. Swift-XRT observations of IceCube 201130A
  78. GRB 201128B: Swift/BAT-GUANO detection and arcminute localization
  79. GRB 201128A: Swift/UVOT Upper Limits
  80. GRB 201128A: Swift-BAT refined analysis
  81. GRB 201128A: Swift-XRT refined Analysis
  82. GRB 201128A: Enhanced Swift-XRT position
  83. GRB 201128A: DDOTI Observations
  84. GRB 201128A: Swift detection of a burst
  85. IceCube-201114A: DECam observations and candidate optical counterpart
  86. IceCube-201120A: Swift-XRT non-detection of 4FGL J2028.6+4110e
  87. IceCube 201114A: Swift followup of Fermi J0703.5+0505
  88. Trigger 1007266: Swift detection of 1A 0535+262
  89. GRB 201116A: NOT optical observations
  90. GRB 201116A: Swift-XRT afterglow detection
  91. GRB 201116A: OSN Afterglow Candidate
  92. Swift Trigger 1006917 is Be/X-ray binary pulsar 1A 0535+262
  93. GRB 201116A: Fermi-LAT detection
  94. GRB 201116A: Tiled Swift observations
  95. Swift XRT observations of the Fermi-LAT source 4FGL J0658.6+0636, positionally consistent with the IceCube high-energy neutrino alert
  96. Swift-XRT observations of IceCube 201114A
  97. Swift Trigger 1005428: Detection of SGR 1830-0645
  98. GRB 201104A: AstroSat CZTI detection
  99. Konus-Wind detection of GRB 201105A
  100. GRB 201104B: 1.3m DFOT optical observations

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