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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"

21525 results found.

  1. GRB 201216A: Swift-XRT observations
  2. GRB 201216C: Enhanced Swift-XRT position
  3. GRB 201216C: VLT afterglow candidate discovery
  4. GRB 201216A: Swift ToO observations
  5. GRB 201216C: Swift-XRT observations
  6. Swift GRB201216.96: Global MASTER-Net observations report
  7. GRB 201216C: Swift detection of a burst
  8. GRB 201216A: Swift/BAT-GUANO detection and arcminute localization
  9. GRB 201214B: MITSuME Akeno optical upper limits
  10. GRB 201214B: Lowell Discovery Telescope optical observations
  11. GRB 201214B: Swift-XRT observations
  12. GRB 201209A: Insight-HXMT/HE detection
  13. GRB 201214A: Swift-XRT observations
  14. GRB 201214B: Swift BAT location of short burst
  15. GRB 201214B: Swift ToO observations
  16. GRB 201214A: Swift ToO observations
  17. GRB 201203A: Zeiss-1000 (Koshka observatory) optical upper limit
  18. GRB 201203A: 1.3m DFOT, optical upper limits
  19. GRB 201209A: Swift/UVOT Upper Limits
  20. GRB 201209A: Swift-BAT refined analysis
  21. GRB 201208A: Swift-XRT afterglow detection
  22. GRB 201208A: LCO observations
  23. GRB 201209A: Swift-XRT refined Analysis
  24. GRB 201209A: Xinglong-2.16m likely optical afterglow detection
  25. GRB 201209A: AstroSat CZTI detection
  26. GRB 201209A: Enhanced Swift-XRT position
  27. IceCube-201130A: Optical and NIR Imaging Follow-up by Kanata Telescope
  28. GRB 201209A: KAIT Optical Upper Limit
  29. GRB 201209A: FRAM-Auger optical limit
  30. GRB 201209A: Swift detection of a burst
  31. Swift GRB201209.24: Global MASTER-Net observations report
  32. GRB 201208A: Fermi-LAT detection
  33. GRB 201208A: Swift ToO observations
  34. GRB 201203A: Swift-BAT refined analysis
  35. Swift follow-up observations of the flat spectrum radio quasar PMN J0206-1150 in the error region of IceCube-201130A
  36. GRB 201203A: GROWTH-India Telescope optical upper limit.
  37. GRB 201203A: MITSuME Okayama optical upper limits
  38. Swift GRB 201203A: Global MASTER-Net observations report
  39. GRB 201203A: Swift-XRT afterglow detection
  40. GRB 201203A: KAIT Optical Upper Limit
  41. GRB 201203A: DDOTI Observations
  42. GRB 201203A: FRAM-Auger optical limit
  43. GRB 201203A: Swift detection of a burst
  44. GRB 201128B: Swift-XRT observations
  45. Swift observations of the Fermi-LAT source 4FGL J0206.4-1151 in the error region of IceCube-201130A
  46. GRB 201128B: Swift ToO observations
  47. Swift-XRT observations of IceCube 201130A
  48. GRB 201128B: Swift/BAT-GUANO detection and arcminute localization
  49. GRB 201128A: Swift/UVOT Upper Limits
  50. GRB 201128A: Swift-BAT refined analysis
  51. GRB 201128A: Swift-XRT refined Analysis
  52. GRB 201128A: Enhanced Swift-XRT position
  53. GRB 201128A: DDOTI Observations
  54. GRB 201128A: Swift detection of a burst
  55. IceCube-201114A: DECam observations and candidate optical counterpart
  56. IceCube-201120A: Swift-XRT non-detection of 4FGL J2028.6+4110e
  57. IceCube 201114A: Swift followup of Fermi J0703.5+0505
  58. Trigger 1007266: Swift detection of 1A 0535+262
  59. GRB 201116A: NOT optical observations
  60. GRB 201116A: Swift-XRT afterglow detection
  61. GRB 201116A: OSN Afterglow Candidate
  62. Swift Trigger 1006917 is Be/X-ray binary pulsar 1A 0535+262
  63. GRB 201116A: Fermi-LAT detection
  64. GRB 201116A: Tiled Swift observations
  65. Swift XRT observations of the Fermi-LAT source 4FGL J0658.6+0636, positionally consistent with the IceCube high-energy neutrino alert
  66. Swift-XRT observations of IceCube 201114A
  67. Swift Trigger 1005428: Detection of SGR 1830-0645
  68. GRB 201104A: AstroSat CZTI detection
  69. Konus-Wind detection of GRB 201105A
  70. GRB 201104B: 1.3m DFOT optical observations
  71. GRB 201104A: Swift-XRT observations
  72. Swift XRT and UVOT detection of ZTF20acozryr/AT2020yxz/GRB201103B
  73. GRB 201015A: Swift-XRT late time observations
  74. Correction to GCN 28843: GBM report of GRB 201105B should have been GRB 201105A
  75. GRB 201104B: Swift/UVOT Detection
  76. GRB 201104B: Swift-XRT refined Analysis
  77. Correcton to GCN 28848: Swift observes ZTF20acozryr
  78. GRB 201104C: Swift ToO observations
  79. GRB 201105A: Swift detected burst and BAT refined analysis
  80. IPN triangulation of GRB 201103B (consistent with ZTF20acozryr/AT2020yxz)
  81. GRB 201104B: Swift-BAT refined analysis
  82. Swift Trigger 1004219: Detection of SGR 1830-0645
  83. GRB 201104A: Tiled Swift observations
  84. GRB 201104A: Fermi-LAT detection
  85. GRB 201104B: Swift/UVOT Detection
  86. GRB 201104B: MASTER optical observation
  87. GRB 201104B: Swift detection of a burst
  88. GRB 201015A: Late X-ray Detections with Chandra
  89. Swift GRB 201031A: Global MASTER-Net observations report
  90. Swift Trigger 1003313 (a.k.a. GRB 201031A) is not an astrophysical event
  91. GRB 201031A: Swift detection of a burst
  92. GRB 201029A: Swift-BAT refined analysis
  93. IceCube 201021A: Swift follow-up of Fermi J1725.5+1312
  94. Swift GRB 201029A: Global MASTER-Net observations report
  95. GRB 201029A: Swift/UVOT Upper Limits
  96. GRB 201029A: Fermi GBM detection
  97. GRB 201029A: Swift-XRT refined Analysis
  98. GRB 201029A: BOOTES-1 optical upper limit
  99. GRB 201029A: Enhanced Swift-XRT position
  100. GRB 201029A: FRAM-ORM optical limit

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