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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"

26125 results found.

  1. GRB 210704A: Assy optical afterglow upper limit
  2. GRB 210704A: OSIRIS/GTC Observations and Archival Detection of the Possible Host Galaxy
  3. GRB 210704A: Gemini-North Infrared Source Detection
  4. GRB 210704A: further TNG optical observations
  5. GRB 210706A: Swift/XRT afterglow confirmation
  6. GRB 210708B: Swift-BAT refined analysis
  7. Swift GRB 210708B: Global MASTER-Net observations report
  8. GRB 210708A: Swift/UVOT Upper Limits
  9. GRB 210708A: Swift-BAT refined analysis
  10. Fermi GBM Sub-Threshold Detection of GRB 210708A
  11. GRB 210708B: Swift detection of a possible burst
  12. GRB 210708A: Swift-XRT refined Analysis
  13. GRB 210708A: Swift detection of a burst
  14. Swift GRB210708.10: Global MASTER-Net observations report
  15. GRB 210704A: CAHA 2.2m telescope optical limit
  16. Fermi GBM Observations of SGR J1935+2154
  17. Swift-BAT detection of a burst from SGR 1935+2154
  18. GRB 210706A: Fermi GBM observation
  19. GRB 210706A: optical upper limit of Sintesz-Newton/CrAO and AS-32/AbAO
  20. Konus-Wind detection of GRB 210706A
  21. GRB 210706A: GIT optical upper limits
  22. GRB 210704A: OAJ T80 multi-color detections
  23. GRB 210706A: Swift-XRT afterglow detection
  24. GRB 210706A: Swift ToO observations
  25. GRB 210706A: Swift/BAT-GUANO detection and arcminute localization
  26. GRB 210704A: OSIRIS/GTC spectroscopy
  27. GRB 210704A: CAHA 2.2m Afterglow Detection
  28. GRB 210704A: Swift/UVOT Upper Limits
  29. GRB 210704A: TNG detection of the optical afterglow candidate
  30. GRB 210704A: Assy optical afterglow candidate
  31. GRB 210704A: DDOTI upper limit
  32. GRB 210704A: possible local hosts
  33. GRB 210704A: Fermi GBM detection
  34. GRB 210704A: Swift-XRT afterglow detection
  35. GRB 210704A: Swift ToO observations
  36. GRB 210702A, Swift-BAT refined analysis
  37. GRB 210702A: BOOTES-3/YA optical counterpart observations
  38. Konus-Wind detection of GRB 210702A
  39. GRB 210702A: Chilescope optical observations
  40. GRB 210702A: iTelescope optical afterglow observations
  41. GRB 210702A: AGILE detection
  42. GRB 210702A: CALET Gamma-Ray Burst Monitor detection
  43. GRB 210619B: JCMT SCUBA-2 sub-mm observations
  44. GRB 210610B: JCMT SCUBA-2 sub-mm observations
  45. GRB 210610A: JCMT SCUBA-2 sub-mm observations
  46. GRB 210702A: Swift-XRT refined Analysis
  47. GRB 210702A: VLT/X-shooter redshift
  48. GRB 210702A: preliminary Swift/UVOT photometry
  49. GRB 210702A: Swift/UVOT redshift
  50. GRB210702A: MeerLICHT multi-colour photometry
  51. Swift GRB 210702A: Global MASTER-Net observations report
  52. Swift GRB210702.80: Global MASTER-Net OT detection
  53. GRB 210702A: Swift detection of a burst with a bright optical counterpart
  54. GRB 210619B: Sayan observatory 1.6-m telescope observations
  55. GRB 210626A: Swift/XRT afterglow confirmation
  56. GRB 210626A: Fermi GBM observation
  57. GRB 210626A: CAHA 2.2m telescope optical limit
  58. GRB 210619B: Deep CAHA 2.2m detection and late-time light curve behavior
  59. GRB 210626A: Ondrejov D50 optical limit
  60. GRB 210626A: GIT optical upper limit
  61. GRB 210626A: Swift-XRT afterglow detection
  62. GRB 210626A: Swift ToO observations
  63. GRB 210626A: Swift/BAT-GUANO detection and arcminute localization
  64. GRB 150428A: late-time radio observations
  65. GRB 210618A: 1.5m OSN optical upper limit
  66. GRB210619B: optical afterglow detection from Konkoly Observatory
  67. GRB 210622A: Swift-XRT observations
  68. GRB 210619B: ASIM observation
  69. GRB 210618A: Swift-XRT afterglow detection
  70. GRB 210622A: Swift ToO observations
  71. GRB 210619B: Even further SAO RAS optical observations
  72. GRB 210622A: Fermi GBM detection
  73. GRB 210619B: Abbey Ridge Observatory optical afterglow observation
  74. GRB 210619B: Further SAO RAS optical observations
  75. GRB 210622A: Swift/BAT-GUANO detection and arcminute localization of a long burst
  76. GRB 210619B: possibility of lensed visible afterglow?
  77. GRB 210619B: AbAO optical observations
  78. Swift Trigger 1057131: detection of a burst from SGR Swift J1555.2-5402
  79. Swift GRB210621.71: Global MASTER-Net observations report
  80. GRB 210619B: NOT optical observations
  81. GRB 210619B: 1.5m OSN optical observation
  82. GRB 210619B: iTelescope optical afterglow observation
  83. GRB 210619B: SAO RAS optical observations
  84. GRB 210619B: TNG NIR observations of the afterglow
  85. GRB 210619B: REM optical/NIR afterglow detection
  86. GRB 210619B: GIT optical follow-up and confirmation of jet-break
  87. GRB 210619B: CALET Gamma-Ray Burst Monitor detection
  88. GRB 210619B: SRG/ART-XC detection
  89. GRB 210619B: Swift-BAT refined analysis
  90. GRB 210619B: steepening of the decay observed at the D50
  91. GRB 210619B: Liverpool Telescope First Hour Observations
  92. GRB 210619B: Fermi GBM detection
  93. GRB 210619B: Swift/UVOT Detection
  94. GRB 210619B: Xinglong TNT optical observations
  95. Konus-Wind detection of GRB 210619B
  96. GRB 210619B: CAHA 2.2m photometric monitoring
  97. GRB 210619B: Liverpool Telescope r'-band observations
  98. GRB 210619B: KAIT Optical Detection
  99. GRB 210619B: Redshift from OSIRIS/GTC
  100. GRB 210619B: Liverpool telescope imaging of a red afterglow

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