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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"

36188 results found.

  1. GRB 210925A: Fermi GBM Final Real-time Localization
  2. GRB 210919A: Chandra rapid ToO upper limit
  3. GRB 210924A: Fermi GBM Final Real-time Localization
  4. GRB 210923B: GECAM detection
  5. Retraction of Fermi GBM GRB 210923A: the trigger is not a GRB
  6. IceCube-210922A: Upper limits from Fermi-GBM Observations
  7. GRB 210919A: DECam Upper Limits
  8. GRB 210923A: Fermi GBM Final Real-time Localization
  9. GRB 210919A: Swift-BAT refined analysis
  10. GRB 210912A: LBT optical observations
  11. GRB 210919A: Lowell Discovery Telescope upper limits (correction to GCN 30859)
  12. GRB 210919a: Lowell Discovery Telescope upper limits
  13. GRB210919A: Keck NIRC2 Kp band upper limits
  14. GRB 210919A: Swift/UVOT Upper Limits
  15. GRB 210919A: LOAO and LSGT optical upper limits
  16. GRB 210919A: MITSuME Akeno optical upper limits
  17. GRB 210919A: Swift-XRT refined Analysis
  18. GRB 210919B: Fermi GBM Final Real-time Localization
  19. GRB 210919A: NOT upper limits
  20. GRB 210919A: AbAO optical upper limit
  21. GRB 210919A: Enhanced Swift-XRT position
  22. GRB 210919A: LCO Optical Upper Limit
  23. GRB 210919A: BOOTES-2/TELMA optical upper limit
  24. Swift GRB 210919A: Global MASTER-Net observations report
  25. GRB 210919A: Swift detection of a short burst
  26. GRB 210912A: BOOTES-5/JGT optical afterglow candidate (Correction to GCNC 30823)
  27. GRB 210917A: Fermi GBM Final Real-time Localization
  28. GRB 210812A is not a compelling example of a lensed GRB
  29. GRB 210909A: Detection by GRBAlpha
  30. GRB 210912A: Swift-BAT refined analysis
  31. GRB 210912A: Tautenburg observations
  32. GRB 210912A: CAHA 2.2m Detection
  33. GRB 210912A: Swift-XRT refined Analysis
  34. GRB 210912A: Swift/UVOT Detection
  35. GRB 210912A: Enhanced Swift-XRT position
  36. GRB 210912A: Host-galaxy candidate in PanSTARRS
  37. GRB 210912A: Mondy optical afterglow confirmation
  38. Swift GRB 210912A: Global MASTER-Net observations report
  39. GRB 210912A: BOOTES-5/JGT optical afterglow candidate
  40. GRB 210912B: Fermi GBM Final Real-time Localization
  41. GRB 210912A: Swift detection of a burst
  42. GRB 210826A: further Swift-XRT observations
  43. GRB 210909B: GECAM detection
  44. GRB 210619B: Maidanak and Assy optical observations, broken power law parametrization
  45. Fermi GRB 210909A: Global MASTER-Net observations report
  46. GRB 210909A: Fermi GBM Final Real-time Localization
  47. GRB 210905A: Swift/UVOT Upper Limits
  48. GRB 210905A: ATCA detection
  49. GRB 210905A: ALMA detection
  50. GRB 210905A: AstroSat CZTI detection
  51. GRB 210905A, GROND observations
  52. Konus-Wind detection of GRB 210905A
  53. Fermi GBM Sub-Threshold Detection of GRB 210905A
  54. Fermi GBM trigger 652585475 / 210906073 is not a GRB
  55. GRB 210905A: Swift-XRT refined Analysis
  56. GRB 210610A: Maidanak and AbAO optical observations
  57. GRB 210827B: GECAM detection
  58. GRB 210905A: DECam Detection
  59. GRB 210905A: REM NIR afterglow detection
  60. GRB 210905A: VLT/X-shooter spectroscopic redshift
  61. GRB 210905A: Continued LCO Optical Observations
  62. GRB 210905A: LCO Optical Detection
  63. GRB 210905A: Enhanced Swift-XRT position
  64. GRB 210901A: Swift/UVOT Upper Limits
  65. Swift GRB 210905A: Global MASTER-Net observations report
  66. GRB 210905A: Swift detection of a burst
  67. Fermi GRB 210904A: Global MASTER-Net observations report
  68. GRB 210904A: Fermi GBM Final Real-time Localization
  69. Fermi GRB 210903A: Global MASTER-Net observations report
  70. GRB 210903C: Fermi GBM Final Real-time Localization
  71. GRB 210820A: TSHAO optical upper limit
  72. Fermi GRB 210903B: Global MASTER-Net observations report
  73. GRB 210901A: GROND observations
  74. GRB 210903B: Fermi GBM Final Localization
  75. GRB 210903A: Fermi GBM Final Real-time Localization
  76. GRB 210901A: Swift-XRT refined Analysis
  77. GRB 210901A: Swift-BAT refined analysis
  78. GRB 210901A: Enhanced Swift-XRT position
  79. GRB 210901A: LCO Optical Upper Limit
  80. Swift GRB 210901A: Global MASTER-Net observations report
  81. GRB 210901A: Swift detection of a burst
  82. GRB 210827A: further Swift-XRT observations
  83. GRB 210822A: CALET Gamma-Ray Burst Monitor detection
  84. GRB 210827A: Swift/UVOT Upper Limits
  85. GRB 210827A: BOOTES-5/JGT optical upper limit
  86. IBAS Alert n. 9366 not a GRB
  87. GRB 210827A: Fermi GBM Observation
  88. GRB 210826A: AstroSat CZTI detection
  89. Fermi GRB 210827A: Global MASTER-Net observations report
  90. Fermi GRB 210827B: Global MASTER-Net observations report
  91. GRB 210827A: Swift-XRT observations
  92. GRB 210827A: Swift ToO observations
  93. GRB 210827A: Swift/BAT-GUANO detection and arcminute localization
  94. GRB 210820A: CAHA 2.2m Optical Detection
  95. GRB 210824A: Swift/UVOT Upper Limits
  96. GRB 210826A: Swift/UVOT Upper Limits
  97. GRB 210827B: BALROG localization (Fermi Trigger 651751821 / GRB 210827424)
  98. GRB 210827B: Fermi GBM Final Real-time Localization
  99. GRB 210826A: Swift-XRT observations
  100. GRB 210827A: Fermi GBM Final Real-time Localization

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