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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

27779 results found.

  1. GRB 240205B: GECAM detection of a long burst
  2. GRB 240204A: Swift-BAT refined analysis
  3. GRB 240205B: Skynet Optical Afterglow Observations
  4. GRB 240205B: BOOTES-7 optical afterglow follow-up
  5. GRB 240205B: MASTER OT J232550.14-550704.6 counterpart detection
  6. GRB 240205B: Swift detection of a burst
  7. GRB 240205B: Fermi GBM Final Real-time Localization
  8. Swift GRB240205.93: Global MASTER-Net observations report
  9. GRB 240204A: Fermi GBM Observation
  10. GRB 240205A: Fermi GBM Final Real-time Localization
  11. GRB 240204a: Liverpool Telescope optical afterglow detection
  12. GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
  13. GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
  14. GRB 240204A: Montarrenti Observatory optical observations
  15. GRB 240204A: Enhanced Swift-XRT position
  16. GRB 240204A: Mondy optical afterglow candidate
  17. GRB 240204A: Swift detection of a burst
  18. IceCube-240204A - IceCube observation of a high-energy neutrino candidate track-like event
  19. GRB 240204A: Fermi GBM Final Real-time Localization
  20. Swift Trigger 1212791 is not an astrophysical event.
  21. Swift-BAT triggers 1212787, 1212789 are not astrophysical.
  22. Konus-Wind detection of GRB 240124B
  23. Konus-Wind detection of GRB 240123C
  24. IPN triangulation of GRB 240124B
  25. GRB 240201A: AstroSat CZTI detection
  26. GRB 240129A: Fermi GBM Observation
  27. IPN triangulation of GRB 240125B (short)
  28. GRB 240129A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  29. IPN triangulation of GRB 240125A (short)
  30. GRB 240128A: Glowbug gamma-ray detection
  31. GRB 240128A: Swift-XRT observations
  32. GRB 240128A: GRBAlpha detection
  33. GRB 240128A: Tiled Swift observations
  34. GRB 240128A: CALET Gamma-Ray Burst Monitor detection
  35. GRB 240128A: MAXI/GSC detection
  36. GRB 240125A: GRBAlpha detection
  37. GRB 240123C: GRBAlpha detection
  38. GRB 240122A: ATCA detection of radio counterpart
  39. GRB 240127A: Fermi GBM Final Real-time Localization
  40. GRB 240125A: CALET Gamma-Ray Burst Monitor detection
  41. Swift Trigger 1211211 and 1211212 are not astrophysical
  42. GRB 240125A: AstroSat CZTI detection of a short burst
  43. GRB 240124B: AstroSat CZTI detection
  44. GRB 240123C: AstroSat CZTI detection
  45. GRB 240125B: Fermi GBM Final Localization
  46. GRB240122A: PRIME near infrared detection
  47. GRB 240123B: Fermi GBM Observation
  48. GRB 240123A: Glowbug gamma-ray detection
  49. GRB 240125A (short): Glowbug gamma-ray detection
  50. GRB 240123B: Swift/BAT-GUANO detection of a long burst
  51. GRB 240123A: GRBAlpha detection
  52. IPN triangulation of GRB 240123C (short)
  53. Swift trigger 1210856 is not astrophysical
  54. GRB 240122B: CALET Gamma-Ray Burst Monitor detection
  55. GRB 240123A: Swift-BAT refined analysis
  56. GRB 240123A : MITSuME Akeno optical afterglow candidate detection
  57. GRB 240123A: Enhanced Swift-XRT position
  58. GRB 240122A: Swift/UVOT Upper Limits
  59. GRB 240123A: Swift-XRT refined Analysis
  60. GRB 240122A: BOOTES-2/TELMA optical upper limit and 1.5m OSN detection
  61. Fermi GBM Sub-Threshold Detection of GRB 240123A
  62. GRB 240123B: Fermi GBM Final Real-time Localization
  63. GRB 240118A: Swift/UVOT Upper Limits
  64. GRB 240122B: Glowbug gamma-ray detection
  65. IceCube-240123A - IceCube observation of a high-energy neutrino candidate track-like event
  66. Konus-Wind detection of GRB 240112A
  67. GRB 240123A: Swift detection of a burst with a possible optical counterpart
  68. Swift GRB240123.46: Global MASTER-Net observations report
  69. GRB 240122A: Swift-XRT afterglow detection
  70. GRB 240122A: VLT/X-shooter redshift confirmation
  71. GRB 240122A: LT non-detection of GOTO candidate counterpart confirms fading
  72. GRB 240122A: Tiled Swift observations
  73. Konus-Wind detection of GRB 240119A (short/hard)
  74. GRB 240122A: MAXI/GSC detection
  75. IPN triangulation of GRB 240119A (short)
  76. GRB 240119A: GECAM detection of a short burst
  77. GRB 240118C: GECAM-B detection of a long burst
  78. GRB 240119A: AstroSat CZTI detection of a short burst
  79. GRB 240118A: Mondy optical observations
  80. GRB 240118A: Swift-XRT afterglow detection
  81. GRB 240118C: Fermi GBM Observation
  82. IceCube-240105A: Detection of NIR flare of PKS 0446+11 with WINTER
  83. GRB 240119A: Fermi GBM Final Localization
  84. GRB 240117A: CALET Gamma-Ray Burst Monitor detection
  85. GRB 240118C: Swift/BAT-GUANO detection of a burst
  86. GRB 240118A: GRBAlpha detection
  87. GRB 240115A: Fermi GBM Observation
  88. Swift triggers 1209631, 1209632, 1209635 and 1209644 are not interesting astrophysical events
  89. GRB 240118D: AstroSat CZTI detection
  90. GRB 240117A: AstroSat CZTI detection
  91. GRB 240118A: Swift ToO observations
  92. GRB 240118A: AbAO optical upper limit
  93. GRB 240118A: NuSTAR Offline Analysis of the GRB
  94. GRB 240117A: Glowbug gamma-ray detection
  95. GRB 240118A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  96. Konus-Wind detection of GRB 240118A
  97. GRB 240118A: NuSTAR Detection of a Long GRB
  98. GRB 240118B: Fermi GBM Final Real-time Localization
  99. GRB 240118A: Fermi-LAT detection
  100. GRID detection of GRB 231230A

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