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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"

27968 results found.

  1. GRB 210528A: Fermi GBM detection
  2. GRB 210528A: AstroSat CZTI detection
  3. GRB 210528B: MAXI/GSC detection
  4. GRB 210527A: Swift-BAT refined analysis
  5. GRB 210528A: Fermi GBM Final Real-time Localization
  6. GRB 210527A: Swift/UVOT Observations
  7. GRB 210527A: GIT optical upper limit
  8. Swift GRB 210527A: Global MASTER-Net observations report
  9. GRB 210527A: Swift-XRT refined Analysis
  10. GRB 210527A: Enhanced Swift-XRT position
  11. GRB 210527A: Swift-XRT observations
  12. GRB 210527A: Swift detection of a burst
  13. Konus-Wind detection of GRB 210524A
  14. IPN triangulation of GRB 210524A
  15. GRB 210524B: Fermi GBM Final Real-time Localization
  16. GRB 210524A: Fermi GBM Final Real-time Localization
  17. GRB 210522A: GECAM detection
  18. GRB 210520A: Swift-XRT observations
  19. GRB 210521A: MAXI/GSC detection
  20. GRB210413B: further Swift-XRT observations
  21. GRB 210520A: Fermi GBM detection
  22. GRB 210520A: Tiled Swift observations
  23. GRB 210520A: Fermi-LAT detection
  24. GRB 210520A: GECAM detection
  25. GRB 210520A: Fermi GBM Final Real-time Localization
  26. GRB 210517A: KCT optical upper limit
  27. IceCube GCN alert 135302_36915486.amon retraction
  28. IPN triangulation of GRB 210518A
  29. GRB 210519A: Fermi GBM Final Localization
  30. Konus-Wind detection of GRB 210514A
  31. GRB 210518A: Fermi GBM Final Real-time Localization
  32. GRB 210517A: Swift-BAT refined analysis
  33. GRB 210517A: Swift-XRT refined Analysis
  34. IceCube-210516A: No significant detection in HAWC
  35. GRB 210517A: Swift/UVOT Upper Limits
  36. GRB 210515C: Swift/UVOT Upper Limits
  37. GRB 210517A: VLT/X-shooter optical afterglow and redshift
  38. GRB 210517A: AGILE detection
  39. GRB 210514A: CALET Gamma-Ray Burst Monitor detection
  40. GRB 210517A: Enhanced Swift-XRT position
  41. Swift GRB 210517A: Global MASTER-Net observations report
  42. GRB 210517A: Swift detection of a burst
  43. GRB 210516A: Fermi GBM Final Real-time Localization
  44. GRB 210515C: LCO Optical Upper Limit
  45. GRB 210504A: LCO Optical Afterglow Detection
  46. IceCube-210516A - IceCube observation of a high-energy neutrino candidate track-like event
  47. GRB 210514A: Swift/UVOT Upper Limits
  48. AMON IC_HAWC NuEm-210515A / NuEm-210515B : No neutrino counterpart detected with ANTARES
  49. GRB 210515C: Swift-XRT refined Analysis
  50. Swift GRB210515.83: Global MASTER-Net observations report
  51. GRB 210515C: Swift-BAT refined analysis
  52. GRB 210515C: Swift detection of a burst
  53. GRB 210514A: Swift-BAT refined analysis
  54. GRB 210515B: Fermi GBM Final Real-time Localization
  55. GRB 210515A: Fermi GBM Final Real-time Localization
  56. Swift GRB210514.71: Global MASTER-Net observations report
  57. GRB 210514A: Swift XRT light curve is fading
  58. GRB 210514A: Swift-XRT refined Analysis
  59. GRB 210514A: Enhanced Swift-XRT position
  60. GRB 210514A: update on the BAT trigger time and burst duration
  61. GRB 210514A: Swift detection of a burst
  62. Konus-Wind detection of GRB 210511B
  63. GRB210510A: Optical afterglow candidate from the Zwicky Transient Facility
  64. IPN triangulation of GRB 210511B
  65. Short GRB 210323A: likely host galaxy detection
  66. IPN triangulation of GRB 210427A
  67. GRB 210511B: AGILE detection
  68. GRB 210511B: GECAM detection
  69. GRB 210511B: Fermi GBM Final Real-time Localization
  70. GRB 210511A: Fermi GBM Final Real-time Localization
  71. GRB 201228B: Swift/BAT-GUANO archival detection and arcminute localization
  72. GRB 200716A: Swift/BAT-GUANO archival detection and arcminute localization
  73. Swift trigger 1047857 is 4U 1700-377
  74. GRB 210510A: Fermi GBM Final Real-time Localization
  75. GRB 210509A: RATIR Optical and NIR Upper Limits
  76. GRB 210509A: Swift/UVOT Upper Limits
  77. GRB 210509A: Swift-XRT refined Analysis
  78. IceCube-210510A - IceCube observation of a high-energy neutrino candidate track-like event
  79. GRB 210509A: Swift-BAT refined analysis
  80. Swift GRB 210509A: Global MASTER-Net observations report
  81. GRB 210509A: Enhanced Swift-XRT position
  82. GRB 210509A: BOOTES-4/MET optical upper limit
  83. GRB 210509A: Swift-XRT observations
  84. GRB 210509A: Swift detection of a burst
  85. GRB 210506A: Swift/BAT-GUANO position retraction
  86. IPN triangulation of GRB 210506A
  87. HAWC-210507A: No neutrino counterpart candidates in ANTARES search
  88. Fermi-LAT Gamma-ray Observations of IceCube-210503A and detection of a new gamma-ray source, Fermi J0931.9+3633
  89. GRB 210507A: Fermi GBM Final Real-time Localization
  90. GRB 210506A: Swift-XRT observations
  91. ZTF21aayokph (AT2021lfa): MASTER OT detection 3h befor ZTF
  92. ZTF21aayokph (AT2021lfa): X-ray Detection with Swift/XRT
  93. Lowell Discovery Telescope Observations of ZTF21aayokph (AT2021lfa)
  94. IceCube-210503A: IceCube observation of a high-energy neutrino candidate event
  95. GRB 210506A: Swift ToO observations
  96. ZTF21aayokph (AT2021lfa): Nanshan/NEXT optical upper limit
  97. GRB 210506A: Swift/BAT-GUANO detection and possible arcminute localization of a short hard burst
  98. GRB 210504A: Lowell Discovery Telescope optical observations
  99. ZTF21aayokph (AT2021lfa): Redshift from Gemini South
  100. GRB 210504A: VLT X-shooter redshift

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