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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 210722A: Nanshan/NEXT optical afterglow observations
  2. GRB 210722A: Swift detection of a burst with a bright optical counterpart
  3. GRB 210712A: Swift-BAT refined analysis
  4. GRB 210712A: Swift-XRT refined Analysis
  5. GRB 210712A: Swift/UVOT Upper Limits
  6. GRB 210712A: BOOTES-3/YA optical upper limit
  7. GRB 210712A: Enhanced Swift-XRT position
  8. GRB 210712A: Swift detection of a burst
  9. GRB210704A: Gemini near-infrared upper limits
  10. GRB 210706A: Swift/XRT afterglow confirmation
  11. GRB 210708B: Swift-BAT refined analysis
  12. Swift GRB 210708B: Global MASTER-Net observations report
  13. GRB 210708A: Swift/UVOT Upper Limits
  14. GRB 210708A: Swift-BAT refined analysis
  15. Fermi GBM Sub-Threshold Detection of GRB 210708A
  16. GRB 210708B: Swift detection of a possible burst
  17. GRB 210708A: Swift-XRT refined Analysis
  18. GRB 210708A: Swift detection of a burst
  19. Swift GRB210708.10: Global MASTER-Net observations report
  20. GRB 210704A: CAHA 2.2m telescope optical limit
  21. Fermi GBM Observations of SGR J1935+2154
  22. Swift-BAT detection of a burst from SGR 1935+2154
  23. GRB 210706A: Fermi GBM observation
  24. GRB 210706A: optical upper limit of Sintesz-Newton/CrAO and AS-32/AbAO
  25. Konus-Wind detection of GRB 210706A
  26. GRB 210706A: GIT optical upper limits
  27. GRB 210704A: OAJ T80 multi-color detections
  28. GRB 210706A: Swift-XRT afterglow detection
  29. GRB 210706A: Swift ToO observations
  30. GRB 210706A: Swift/BAT-GUANO detection and arcminute localization
  31. GRB 210704A: OSIRIS/GTC spectroscopy
  32. GRB 210704A: CAHA 2.2m Afterglow Detection
  33. GRB 210704A: Swift/UVOT Upper Limits
  34. GRB 210704A: Assy optical afterglow candidate
  35. GRB 210704A: DDOTI upper limit
  36. GRB 210704A: possible local hosts
  37. GRB 210704A: Fermi GBM detection
  38. GRB 210704A: Swift-XRT afterglow detection
  39. GRB 210704A: Swift ToO observations
  40. GRB 210702A, Swift-BAT refined analysis
  41. GRB 210702A: BOOTES-3/YA optical counterpart observations
  42. Konus-Wind detection of GRB 210702A
  43. GRB 210702A: Chilescope optical observations
  44. GRB 210702A: AGILE detection
  45. GRB 210702A: CALET Gamma-Ray Burst Monitor detection
  46. GRB 210619B: JCMT SCUBA-2 sub-mm observations
  47. GRB 210610B: JCMT SCUBA-2 sub-mm observations
  48. GRB 210610A: JCMT SCUBA-2 sub-mm observations
  49. GRB 210702A: Swift-XRT refined Analysis
  50. GRB 210702A: VLT/X-shooter redshift
  51. GRB 210702A: preliminary Swift/UVOT photometry
  52. GRB 210702A: Swift/UVOT redshift
  53. GRB210702A: MeerLICHT multi-colour photometry
  54. Swift GRB 210702A: Global MASTER-Net observations report
  55. Swift GRB210702.80: Global MASTER-Net OT detection
  56. GRB 210702A: Swift detection of a burst with a bright optical counterpart
  57. GRB 210619B: Sayan observatory 1.6-m telescope observations
  58. GRB 210626A: Swift/XRT afterglow confirmation
  59. GRB 210626A: Fermi GBM observation
  60. GRB 210626A: CAHA 2.2m telescope optical limit
  61. GRB 210626A: Ondrejov D50 optical limit
  62. GRB 210626A: GIT optical upper limit
  63. GRB 210626A: Swift-XRT afterglow detection
  64. GRB 210626A: Swift ToO observations
  65. GRB 210626A: Swift/BAT-GUANO detection and arcminute localization
  66. GRB 150428A: late-time radio observations
  67. GRB 210618A: 1.5m OSN optical upper limit
  68. GRB 210622A: Swift-XRT observations
  69. GRB 210619B: ASIM observation
  70. GRB 210618A: Swift-XRT afterglow detection
  71. GRB 210622A: Swift ToO observations
  72. GRB 210619B: Even further SAO RAS optical observations
  73. GRB 210622A: Fermi GBM detection
  74. GRB 210619B: Further SAO RAS optical observations
  75. GRB 210622A: Swift/BAT-GUANO detection and arcminute localization of a long burst
  76. Swift Trigger 1057131: detection of a burst from SGR Swift J1555.2-5402
  77. Swift GRB210621.71: Global MASTER-Net observations report
  78. GRB 210619B: NOT optical observations
  79. GRB 210619B: 1.5m OSN optical observation
  80. GRB 210619B: SAO RAS optical observations
  81. GRB 210619B: GIT optical follow-up and confirmation of jet-break
  82. GRB 210619B: CALET Gamma-Ray Burst Monitor detection
  83. GRB 210619B: SRG/ART-XC detection
  84. GRB 210619B: Swift-BAT refined analysis
  85. GRB 210619B: Liverpool Telescope First Hour Observations
  86. GRB 210619B: Fermi GBM detection
  87. GRB 210619B: Swift/UVOT Detection
  88. GRB 210619B: Xinglong TNT optical observations
  89. Konus-Wind detection of GRB 210619B
  90. GRB 210619B: CAHA 2.2m photometric monitoring
  91. GRB 210619B: Liverpool Telescope r'-band observations
  92. GRB 210619B: KAIT Optical Detection
  93. GRB 210619B: Redshift from OSIRIS/GTC
  94. GRB 210619B: Fermi-LAT detection
  95. GRB 210619B: Swift-XRT refined Analysis
  96. GRB 210619B: SARA-KP 0.9m Optical Afterglow Detection
  97. GRB 210619B: Enhanced Swift-XRT position
  98. GECAM detection of GRB 210619B
  99. Swift GRB210619.99: Global MASTER-Net OT detection
  100. GRB 210619B: Swift detection of a bright burst and optical counterpart

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