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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 210104B: Nanshan/NEXT optical upper limit
  2. GRB 210104B: BOOTES network optical upper limit
  3. GRB 210104A: MASTER OT rebrightening detection
  4. GRB 210104A: Swift/UVOT Detection
  5. GRB 210104A: Fermi GBM detection
  6. GRB 210104A: Enhanced Swift-XRT position
  7. GRB 210102B: Tiled Swift observations
  8. GRB 210104B: Swift detection of a burst
  9. Swift GRB210104.88: Global MASTER-Net observations report
  10. GRB 210104A: MITSuME Ishigaki optical observation
  11. GRB 210102B: Assy optical observations
  12. GRB 210104A: MITSuME Akeno optical observation
  13. GRB 210104A: BOOTES-4/MET early optical afterglow detection
  14. GRB 210104A: Swift detection of a burst with a bright optical counterpart
  15. GRB 210102C: Swift-BAT refined analysis
  16. GRB 210102B: Swift-XRT observations
  17. GRB 210102C: Fermi GBM detection
  18. Swift GRB 210102C: Global MASTER-Net observations report
  19. GRB 210102C: Swift detection of a burst
  20. GRB 210102B: Tiled Swift observations
  21. Swift Trigger 1015615 is not a GRB
  22. Swift GRB210102.01: Global MASTER-Net observations report
  23. GRB 201229A: Swift/UVOT Detection
  24. GRB 201227A: Chilescope optical observations, possible optical counterpart
  25. GRB 201227A: GRAWITA VST-ESO PARANAL observations
  26. GRB 201229A: AbAO optical afterglow detection, TSHAO optical upper limit
  27. GRB 201229A: SAO RAS optical observations
  28. GRB 201229A: Nanshan/NEXT optical upper limit
  29. GRB 201227A: Swift-XRT observations
  30. GRB 201223A: SVOM-GWAC detected the optical counterpart during prompt emission phase
  31. GRB 201229A: Swift-XRT refined Analysis
  32. GRB 201229A: Swift-BAT refined analysis
  33. GRB 201229A: Enhanced Swift-XRT position
  34. GRB 201229A: Swift detection of a burst with a possible optical counterpart
  35. GRB 201227A: Tiled Swift observations
  36. GRB 201227A: Swift ToO observations
  37. IPN triangulation of GRB 201227A (short)
  38. GRB 201223A: AROMA-N Optical Observation
  39. GRB 201223A: Swift/UVOT Detection
  40. GRB 201223A: HCT optical upper limit
  41. GRB 201223A: 1.3m DFOT and 1.04m ST optical observations
  42. GRB 201223A: Swift-XRT refined Analysis
  43. GRB 201223A: Enhanced Swift-XRT position
  44. GRB 201223A: GROWTH-India Telescope (GIT) photometric follow-up.
  45. GRB 201223A: MITSuME Akeno optical observation
  46. GRB 201223A: Swift-BAT refined analysis
  47. GRB 201223A: Fermi GBM Detection
  48. GRB 201223A: BOOTES-4/MET early optical observation
  49. GRB 201223A: Nanshan/NEXT early optical afterglow detection
  50. GRB 201223A: Swift detection of a burst with a bright optical counterpart
  51. Swift GRB201223.75: Global MASTER-Net OT detection
  52. Swift GRB201223.75: Global MASTER-Net observations report
  53. Swift-XRT observations of Icecube 201222A
  54. GRB 201221A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
  55. GRB 201221D: MMT MMIRS detection of marginally extended source
  56. GRB 201221D: LCOGT upper limits
  57. GRB 201221D: Fermi GBM detection
  58. GRB 201221D: Swift-BAT refined analysis
  59. Swift Trigger 1014012 (possible GRB 201221C) is likely not an astrophysical event
  60. GRB 201216A - further Swift-XRT observations
  61. GRB 201221D: Archival PS1 Imaging of the Putative Host Galaxy
  62. Konus-Wind detection of GRB 201221D (short)
  63. GRB 201221D: Swift/UVOT Upper Limits
  64. GRB 201221D: Lowell Discovery Telescope afterglow observations
  65. GRB 201221D: FRAM-ORM optical limit
  66. GRB 201221D: Swift-XRT refined Analysis
  67. Swift GRB 201221D: Global MASTER-Net observations report
  68. GRB 201221D: Enhanced Swift-XRT position
  69. GRB 201221D: Nanshan/NEXT early optical upper limit
  70. GRB 201221D: candidate optical counterpart from the NOT
  71. GRB 201221A: Swift-BAT refined analysis
  72. GRB 201221D: Prompt enhanced Swift-XRT position
  73. GRB 201221D: Swift detection of a bright short burst
  74. correction to GCN 29110 - Fermi GBM Sub-Threshold Detection of GRB 201221A
  75. Fermi GBM Sub-Threshold Detection of GRB 201221A
  76. GRB 201221A: Swift/UVOT Upper Limits
  77. GRB 201221A: Swift-XRT refined Analysis
  78. GRB 201221C: MASTER optical observtion
  79. Swift Trigger 1014012: possible GRB 201221C
  80. GRB 201221A: Enhanced Swift-XRT position
  81. GRB 201221A: VLT/X-shooter afterglow discovery and spectroscopic redshift z = 5.7
  82. GRB 201221A: FRAM-Auger optical limit
  83. Swift GRB 201221A: Global MASTER-Net observations report
  84. GRB 201221A: Prompt enhanced Swift-XRT position
  85. GRB 201221A: Swift detection of a burst
  86. GRB 201209A: Mondy optical observations, afterglow confirmation
  87. GRB 201214A: TSHAO optical upper limit
  88. GRB 201214A: Swift-XRT afterglow detection
  89. GRB 201214A: 1.3m DFOT, optical upper limits
  90. IPN triangulation of GRB 201218A
  91. GRB201216C: No significant detection in HAWC
  92. GRB 201216C: Liverpool Telescope First Hour Observations
  93. Konus-Wind detection of GRB 201216C
  94. GRB 201216C: Swift-BAT refined analysis
  95. GRB 201216C: Fermi-LAT upper limit
  96. GRB 201216C: MAGIC detection in very high energy gamma rays
  97. GRB 201216C: AstroSat CZTI detection
  98. GRB 201216C: Fermi GBM detection
  99. GRB 201216A: Fermi GBM detection
  100. GRB 201216C: Swift/UVOT Upper Limits

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