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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 210928A: MeerKAT detection
  2. Correction to GCN 30915: GRB 210928A: Swift-XRT analysis
  3. GRB 210928A: Kinder SLT-40cm optical limits
  4. GRB 210930A: Swift-BAT refined analysis
  5. SGR 1935+2154: Swift/BAT-GUANO detection and arcminute localization
  6. GRB 210928A: Swift-XRT analysis (replaces GCN 30914)
  7. GRB 210928A: Swift-XRT refined Analysis
  8. GRB 210928A: Fermi-LAT detection
  9. Swift GRB211001.03 / trigger 1076121 : MASTER OT retraction
  10. GRB 210930A: CAHA 2.2m telescope optical limit
  11. GRB 210927A: GIT optical follow-up of ZTF21acdwctm.
  12. Swift GRB211001.03: Global MASTER-Net observations report
  13. Swift Trigger 1076121 is not a GRB
  14. Swift GRB211001.03: Global MASTER-Net OT detection
  15. GRB 210930A: Swift/UVOT Upper Limits
  16. GRB 210930A: Swift-XRT refined Analysis
  17. Swift GRB 210930A: Global MASTER-Net observations report
  18. GRB 210930A: Enhanced Swift-XRT position
  19. GRB 210930A: Swift detection of a burst
  20. IPN triangulation of GRB 210925B
  21. GRB 210919A: iTelescope T-11 upper limits
  22. GRB 210919A OSN 1.5m Source Confirmation
  23. GRB 210919A CAHA 2.2m Observations: Afterglow/Host Galaxy Candidate
  24. GRB 210919A: Chandra rapid ToO upper limit
  25. IceCube-210922A: No Candidate Counterparts from Swift/XRT follow up observations
  26. GRB 210919A: DECam Upper Limits
  27. GRB 210919A: Swift-BAT refined analysis
  28. GRB 210912A: LBT optical observations
  29. GRB 210919A: Lowell Discovery Telescope upper limits (correction to GCN 30859)
  30. GRB210919A: Keck NIRC2 Kp band upper limits
  31. GRB 210919A: Swift/UVOT Upper Limits
  32. GRB 210919A: LOAO and LSGT optical upper limits
  33. GRB 210919A: MITSuME Akeno optical upper limits
  34. GRB 210919A: Swift-XRT refined Analysis
  35. GRB 210919A: NOT upper limits
  36. GRB 210919A: AbAO optical upper limit
  37. GRB 210919A: Enhanced Swift-XRT position
  38. GRB 210919A: LCO Optical Upper Limit
  39. GRB 210919A: BOOTES-2/TELMA optical upper limit
  40. Swift GRB 210919A: Global MASTER-Net observations report
  41. GRB 210919A: Swift detection of a short burst
  42. Swift trigger 1073821: detection of IGR J16418-4532
  43. GRB 210912A: BOOTES-5/JGT optical afterglow candidate (Correction to GCNC 30823)
  44. GRB 210912A: Swift-BAT refined analysis
  45. GRB 210912A: CAHA 2.2m Detection
  46. GRB 210912A: Swift-XRT refined Analysis
  47. GRB 210912A: Swift/UVOT Detection
  48. GRB 210912A: Enhanced Swift-XRT position
  49. GRB 210912A: Host-galaxy candidate in PanSTARRS
  50. GRB 210912A: Mondy optical afterglow confirmation
  51. Swift GRB 210912A: Global MASTER-Net observations report
  52. GRB 210912A: BOOTES-5/JGT optical afterglow candidate
  53. GRB 210912A: Swift detection of a burst
  54. Swift GRB210910.42: Global MASTER-Net observations report
  55. IPN triangulation of a bright burst from SGR 1935+2154
  56. GRB 210826A: further Swift-XRT observations
  57. Swift detection of a burst from SGR Swift J1555.2-5402
  58. GRB 210619B: Maidanak and Assy optical observations, broken power law parametrization
  59. GRB 210905A: Swift/UVOT Upper Limits
  60. GRB 210905A: AstroSat CZTI detection
  61. GRB 210905A, GROND observations
  62. Konus-Wind detection of GRB 210905A
  63. Fermi GBM Sub-Threshold Detection of GRB 210905A
  64. GRB 210905A: Swift-XRT refined Analysis
  65. GRB 210610A: Maidanak and AbAO optical observations
  66. GRB 210905A: DECam Detection
  67. GRB 210905A: REM NIR afterglow detection
  68. GRB 210905A: VLT/X-shooter spectroscopic redshift
  69. GRB 210905A: Continued LCO Optical Observations
  70. GRB 210905A: LCO Optical Detection
  71. GRB 210905A: Enhanced Swift-XRT position
  72. GRB 210901A: Swift/UVOT Upper Limits
  73. Swift GRB 210905A: Global MASTER-Net observations report
  74. GRB 210905A: Swift detection of a burst
  75. Swift GRB210903.59: Global MASTER-Net observations report
  76. Swift GRB210903.58: Global MASTER-Net observations report
  77. Swift GRB210903.58: Global MASTER-Net observations report
  78. GRB 210820A: TSHAO optical upper limit
  79. GRB 210901A: GROND observations
  80. Fermi GBM observation of a burst from SGR J1555.2-5402
  81. GRB 210901A: Swift-XRT refined Analysis
  82. GRB 210901A: Swift-BAT refined analysis
  83. GRB 210901A: Enhanced Swift-XRT position
  84. GRB 210901A: LCO Optical Upper Limit
  85. Swift GRB 210901A: Global MASTER-Net observations report
  86. GRB 210901A: Swift detection of a burst
  87. GRB 210827A: further Swift-XRT observations
  88. GRB 210822A: CALET Gamma-Ray Burst Monitor detection
  89. GRB 210827A: Swift/UVOT Upper Limits
  90. GRB 210827A: BOOTES-5/JGT optical upper limit
  91. GRB 210827A: Fermi GBM Observation
  92. GRB 210827A: Swift-XRT observations
  93. GRB 210827A: Swift ToO observations
  94. GRB 210827A: Swift/BAT-GUANO detection and arcminute localization
  95. GRB 210820A: CAHA 2.2m Optical Detection
  96. GRB 210824A: Swift/UVOT Upper Limits
  97. GRB 210826A: Swift/UVOT Upper Limits
  98. GRB 210826A: Swift-XRT observations
  99. GRB 210822A: CAHA 2.2m observations
  100. GRB 210824A: Swift-BAT refined analysis

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