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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"

26120 results found.

  1. GRB 211129A: Enhanced Swift-XRT position
  2. IPN triangulation of GRB 211118A
  3. GRB 211129A: MITSuME Akeno optical upper limits
  4. GRB 211129A: Swift detection of a burst
  5. GRB 211120548: Fermi GBM observation
  6. Chandra observations of GRB 210905A
  7. GRB 211118A: Fermi GBM detection
  8. IPN triangulation of GRB 211124A (short)
  9. GRB 211124A: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  10. Trigger_21473: Tiled Swift observations
  11. GRB 211023B: LBT likely spectroscopic redshift of the host galaxy
  12. GRB 211120B: Swift/BAT-GUANO detection outside the coded FOV
  13. GRB 211118A: AstroSat CZTI detection
  14. GRB 211023A: optical observations and photometric evidence of supernova
  15. GRB211118A: Swift/BAT-GUANO detection outside the coded FOV
  16. Konus-Wind detection of GRB 211107B
  17. GRB 211023A: classification and SPI-ACS/INTEGRAL registration
  18. GRB 211106A: Swift/UVOT upper limits
  19. IPN triangulation of GRB 211106A (short)
  20. Short GRB 211106A: spectroscopy of galaxies in the field
  21. GRB 211107B: Swift-XRT afterglow detection
  22. GRB 211106A: VLT/FORS2 optical observations
  23. GRB 211106A, GROND observations
  24. GRB 211106A: Swift-XRT afterglow detection
  25. GRB 211023A: SAO RAS optical observations
  26. GRB 211107B: Swift-XRT observations
  27. MeerLICHT follow-up of GRB 211106A
  28. GRB 211107B: Swift ToO observations
  29. GRB 211107B: Swift/BAT detection
  30. GRB 211023A: A BdHN of type I
  31. Fermi GBM Sub-Threshold Detection of GRB 211106A
  32. Konus-Wind detection of GRB 211106A
  33. GRB 211023A: BTA spectroscopic redshift
  34. GRB 211106A: Swift-XRT observations
  35. GRB 211106A: Swift ToO observations
  36. GRB 211106A: Swift/BAT-GUANO candidate arcminute localization of a short burst
  37. GRB 211105A: Swift/BAT-GUANO detection outside the coded FOV
  38. Swift Trigger 1082569 is probably not a GRB
  39. GRB 211023A: optical detection by SBT in Ondrejov
  40. GRB 211023A: continued 1.3m DFOT Optical Observations and possible jet break
  41. GRB 211024A: MITSuME Akeno optical observation
  42. GRB 211023B: MITSuME Akeno optical upper limits
  43. GRB 211024B: Optical afterglow observation by Ondrejov D50
  44. GRB 211024A: 1.3m DFOT observations
  45. IPN triangulation of GRB 211022A
  46. GRB 211023A: 1.3m DFOT Optical Observations
  47. GRB 2121023B: 6 GHz VLA radio upper limit
  48. GRB 211023A: Terskol optical observations
  49. AMON NuEm-211020A: No Candidate Counterparts from Swift-XRT follow up observations
  50. GRB 211023A: continued Mondy optical observations
  51. GRB 211024A: Swift-XRT source 4 is not an afterglow.
  52. GRB 211023B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  53. GRB 211024A: Possible afterglow candidate from GIT
  54. GRB 211024A: Swift-XRT observations
  55. GRB 211024A: Fermi GBM detection
  56. GRB 211018A: Swift-XRT observations
  57. GRB 211025A: Optical Afterglow Detection
  58. GRB211023A: optical afterglow detection from Konkoly Observatory
  59. GRB 211024A: Swift ToO observations
  60. GRB 211024A: Swift/BAT-GUANO detection and candidate arcminute localization of a short burst
  61. GRB 211024B: Swift/UVOT detection
  62. GRB 211023A: Mondy optical observations
  63. GRB 211023B: Mondy optical afterglow confirmation
  64. Swift GRB 211025A: Global MASTER-Net observations report
  65. GRB 211023B: LDT Optical Afterglow Detection
  66. GRB 211025A: Swift-BAT refined analysis
  67. GRB 211025A: Swift-XRT refined Analysis
  68. GRB 211024B: CAHA 2.2m Detection; ultra-long GRB?
  69. GRB 211024B: Swift-XRT refined Analysis
  70. Possible Short GRB 211023B: CAHA 2.2m Detection
  71. GRB 211025A: Swift/UVOT Detection
  72. GRB 211023A: 1.5m OSN optical observation
  73. GRB 211024B: Swift-BAT refined analysis
  74. GRB 210610B: Sintesz-Newton/CrAO optical observations
  75. GRB 211025A: Enhanced Swift-XRT position
  76. GRB 211025A: Swift detection of a burst
  77. GRB 211024B: Nanshan/NEXT optical afterglow detection
  78. GRB 210919A: FORS2/VLT observations
  79. GRB 211023A: OAJ Bright Afterglow Confirmation
  80. Swift GRB 211024B: Global MASTER-Net observations report
  81. GRB 211024B: Swift detection of a burst
  82. GRB 211023B: Swift-BAT refined analysis
  83. GRB 211023B: BOOTES-4/MET and 1.5m OSN optical upper limit
  84. GRB 211023B: Swift/UVOT Detection
  85. GRB 211023B: TSHAO optical observation
  86. GRB 211023B: Swift-XRT refined Analysis
  87. GRB 211023B: Enhanced Swift-XRT position
  88. Swift GRB 211023B: Global MASTER-Net observations report
  89. GRB 211023A: Fermi-LAT detection
  90. GRB 211023B: Swift detection of a possibly short burst with an optical counterpart
  91. IPN Triangulation of GRB 210927B
  92. GRB 211018A: Swift ToO observations
  93. BepiColombo MGNS joins the IPN
  94. GRB 211018A: Fermi-LAT detection
  95. Swift GRB211017.99: Global MASTER-Net observations report
  96. Swift trigger 1078701: MITSuME Akeno optical upper limits
  97. GRB 210919A: LDT optical observations and candidate host galaxies
  98. Swift Trigger 1078701: Mondy, CrAO, AbAO observations, possible optical counterpart
  99. Swift GRB211010.45: Global MASTER-Net observations report
  100. Swift Trigger 1078701 is probably not a GRB

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