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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"

22215 results found.

  1. GRB 211204C: Swift/BAT-GUANO detection outside the coded FOV
  2. Fermi GRB 211204C: Global MASTER-Net observations report
  3. Fermi GRB 211204B: Global MASTER-Net observations report
  4. Fermi GRB 211204A: Global MASTER-Net observations report
  5. Swift GRB 211203A: Global MASTER-Net observations report
  6. Konus-Wind detection of GRB 211130A
  7. GRB 211201A: Swift/BAT-GUANO detection likely outside the coded FOV
  8. Fermi GRB 211201A: Global MASTER-Net observations report
  9. Fermi GRB 211130A: Global MASTER-Net observations report
  10. GRB 211129A: Swift/UVOT Upper Limits
  11. GRB 211106A: HST Observations
  12. GRB 211106A: Chandra Observations
  13. Swift GRB 211129A: Global MASTER-Net observations report
  14. IceCube-211125A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  15. GRB 211023A: Xinglong 2.16m optical observations
  16. GRB 211023A: Xinglong 2.16m optical observations
  17. Fermi-LAT Gamma-ray Observations of IceCube-211125A
  18. Konus-Wind detection of GRB 211120A
  19. Chandra observations of GRB 210905A
  20. IceCube Alert 211125.27: Global MASTER-Net observations report
  21. Fermi-LAT Gamma-ray Observations of IceCube-211123A
  22. IceCube-211123A: INTEGRAL was inactive at the time of the event
  23. IceCube-211123A: Upper limits from Fermi-GBM Observations
  24. IceCube-211023A: not observable by Fermi-GBM
  25. GRB 211124A: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  26. IceCube Alert 211123.60: Global MASTER-Net observations report
  27. Fermi trigger No 659413798: Global MASTER-Net observations report
  28. Trigger_21473: Tiled Swift observations
  29. GRB 211023B: LBT likely spectroscopic redshift of the host galaxy
  30. Alert from the HAWC Burst Monitor HAWC-211123A
  31. Fermi trigger No 659183098: Global MASTER-Net observations report
  32. Fermi trigger No 659106591: Global MASTER-Net observations report
  33. GRB 211120B: Swift/BAT-GUANO detection outside the coded FOV
  34. GRB 211023A: optical observations and photometric evidence of supernova
  35. Fermi-LAT Gamma-ray Observations of IceCube-211117A
  36. GRB211118A: Swift/BAT-GUANO detection outside the coded FOV
  37. Fermi trigger No 658971499: Global MASTER-Net observations report
  38. Fermi-LAT Gamma-ray Observations of IceCube-211116A
  39. IceCube Alert 211116.44: Global MASTER-Net observations report
  40. Fermi trigger No 658755664: Global MASTER-Net observations report
  41. Fermi trigger No 658764238: Global MASTER-Net observations report
  42. GRB 211115A: CALET Gamma-Ray Burst Monitor detection
  43. Fermi trigger No 658686687: Global MASTER-Net observations report
  44. Fermi GRB 211112A: Global MASTER-Net observations report
  45. Fermi trigger No 658214822: Global MASTER-Net observations report
  46. GRB 211107B: Swift-XRT afterglow detection
  47. GRB 211106A: VLT/FORS2 optical observations
  48. GRB 211106A, GROND observations
  49. GRB 211106A: Swift-XRT afterglow detection
  50. Fermi GRB 211109B: Global MASTER-Net observations report
  51. GRB 211023A: SAO RAS optical observations
  52. GRB 211107B: Swift-XRT observations
  53. MeerLICHT follow-up of GRB 211106A
  54. GRB 211107B: Swift ToO observations
  55. Fermi GRB 211109A: Global MASTER-Net observations report
  56. GRB 211107B: Swift/BAT detection
  57. GRB 211023A: A BdHN of type I
  58. GRB 211106A: Swift-XRT observations
  59. GRB 211106A: Swift ToO observations
  60. GRB 211106A: Swift/BAT-GUANO candidate arcminute localization of a short burst
  61. GRB 211105A: MASTER optical inspection
  62. GRB 211105A: Swift/BAT-GUANO detection outside the coded FOV
  63. GRB 211023A: continued 1.3m DFOT Optical Observations and possible jet break
  64. Fermi trigger No 657742914: Global MASTER-Net observations report
  65. GRB 211023B: Subaru optical observation
  66. Fermi GRB 211102A: Global MASTER-Net observations report
  67. GRB 211024B: Optical afterglow observation by Ondrejov D50
  68. GRB 211024A: 1.3m DFOT observations
  69. Fermi GRB 211031A: Global MASTER-Net observations report
  70. GRB 211023A: 1.3m DFOT Optical Observations
  71. Konus-Wind detection of GRB 211023A
  72. GRB 2121023B: 6 GHz VLA radio upper limit
  73. GRB 211023A: Terskol optical observations
  74. AMON NuEm-211020A: No Candidate Counterparts from Swift-XRT follow up observations
  75. GRB 211023A: continued Mondy optical observations
  76. GRB 211024A: Swift-XRT source 4 is not an afterglow.
  77. GRB 211023B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  78. Fermi GRB 211027A: Global MASTER-Net observations report
  79. GRB 211024A: Possible afterglow candidate from GIT
  80. GRB 211024A: Swift-XRT observations
  81. GRB 211018A: Swift-XRT observations
  82. GRB 211024A: Swift ToO observations
  83. GRB 211024A: Swift/BAT-GUANO detection and candidate arcminute localization of a short burst
  84. GRB 211023A: Mondy optical observations
  85. GRB 211023B: Gemini-North Optical Observations
  86. Swift GRB 211025A: Global MASTER-Net observations report
  87. GRB 211023B: LDT Optical Afterglow Detection
  88. GRB 211025A: Swift/UVOT Detection
  89. GRB 211023A: 1.5m OSN optical observation
  90. GRB 210610B: Sintesz-Newton/CrAO optical observations
  91. GRB 211024B: Nanshan/NEXT optical afterglow detection
  92. GRB 210919A: FORS2/VLT observations
  93. GRB 211023A: OAJ Bright Afterglow Confirmation
  94. Swift GRB 211024B: Global MASTER-Net observations report
  95. Fermi-LAT Gamma-ray Observations of IceCube-211023A
  96. GRB 211023A: MASTER OT J045237.07+851925.2 - optical counterpart discovery
  97. GRB 211023B: Swift/UVOT Detection
  98. GRB 211023B: RATIR Optical and NIR Upper Limits
  99. Fermi GRB 211023A: Global MASTER-Net observations report
  100. Swift GRB 211023B: Global MASTER-Net observations report

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