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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"

11113 results found.

  1. Fermi GRB 240220A: Global MASTER-Net observations report
  2. GRB 240220A: Fermi GBM Final Real-time Localization
  3. Konus-Wind detection of GRB 240218A
  4. GRB 240218A: VLT/X-shooter redshift of z = 6.782
  5. GRB 240218A: Fermi GBM Detection
  6. GRB 240215A: Fermi GBM Observation
  7. GRB 240216A: GRBAlpha detection
  8. GRB 240215B: GRBAlpha detection
  9. IPN triangulation of GRB 240209A
  10. Fermi trigger No 729914426: Global MASTER-Net observations report
  11. Gamma-ray flaring activity from the blazar 1ES 1959+650 observed by the Fermi-LAT
  12. GRB 240213A: GRBAlpha detection
  13. GRB 240215C: Fermi GBM Final Real-time Localization
  14. GRB 240215B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  15. Fermi GRB 240216A: Global MASTER-Net observations report
  16. GRB 240216A: Fermi GBM Final Real-time Localization
  17. Fermi trigger No 729719508: Global MASTER-Net observations report
  18. GRB 240215A: Swift/BAT-GUANO localization of a burst
  19. Fermi trigger No 729703985: Global MASTER-Net observations report
  20. Fermi trigger No 729650855: Global MASTER-Net observations report
  21. GRB 240209A: Classification of AT2024cew/GOTO24pw as Type Ia-pec supernova
  22. GRB 240209A: Fermi GBM observation
  23. GRB 240213A: Glowbug gamma-ray detection
  24. GRB240209A: OHP/T193 detection of the GOTO afterglow candidate AT2024cew / GOTO24pw
  25. GRB 240209A: Wendelstein Optical Observations
  26. GRB 240213A: BALROG localization (Fermi Trigger / GRB 240213841)
  27. Fermi GRB 240213A: Global MASTER-Net observations report
  28. GRB 240213A: Fermi GBM Final Real-time Localization
  29. GRB 240209A: NOEMA non-detection of AT2024cew / GOTO24pw counterpart candidate
  30. GRB 240209A: NOT photometry of the AT2024cew / GOTO24pw counterpart candidate
  31. GRB 240209A: GOTO optical counterpart candidate
  32. Konus-Wind detection of GRB 240204A
  33. Konus-Wind detection of GRB 240205A (short)
  34. GRB 240209A: Fermi GBM Final Localization
  35. Fermi trigger No 729152364: Global MASTER-Net observations report
  36. IPN triangulation of GRB 240205A (short)
  37. Fermi-LAT gamma-ray observations of IceCube-240204A
  38. GRB 240205B: PRIME near infrared detection
  39. GRB 240205A (short): Glowbug gamma-ray detection
  40. GRB 240205B: AstroSat CZTI detection
  41. Fermi trigger No 729012023: Global MASTER-Net observations report
  42. Konus-Wind detection of GRB 240205B (long / very soft)
  43. GRB 240207A: Fermi GBM Final Real-time Localization
  44. GRB 240205B: VLT/X-shooter redshift
  45. GRB 240205B: CALET Gamma-Ray Burst Monitor detection
  46. GRB 240205B: BOOTES-6 optical afterglow follow-up
  47. GRB 240205B: ATCA detection of radio counterpart
  48. GRB 240205B: REM detection of the optical/NIR afterglow
  49. GRB 240205B: Fermi GBM Observation
  50. GRB 240204A: AstroSat CZTI detection
  51. GRB 240204A: Mondy optical afterglow observations
  52. GRB 240204A : OHP/T193/T120 optical afterglow fading detection
  53. GRB 240205B: GECAM detection of a long burst
  54. GRB 240205B: Skynet Optical Afterglow Observations
  55. GRB 240205B: BOOTES-7 optical afterglow follow-up
  56. Fermi trigger No 728749569: Global MASTER-Net observations report
  57. GRB 240205B: MASTER OT J232550.14-550704.6 counterpart detection
  58. GRB 240205B: Fermi GBM Final Real-time Localization
  59. GRB 240204A: Fermi GBM Observation
  60. GRB 240205A: Fermi GBM Final Real-time Localization
  61. GRB 240204a: Liverpool Telescope optical afterglow detection
  62. GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
  63. Fermi Gamma-ray Burst Monitor trigger 728740048/240204491 is not a GRB
  64. Fermi trigger No 728796365: Global MASTER-Net observations report
  65. GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
  66. GRB 240204A: Montarrenti Observatory optical observations
  67. GRB 240204A: Mondy optical afterglow candidate
  68. Fermi Gamma-ray Burst Monitor trigger 728706420/240204102 is not a GRB
  69. Fermi GRB 240204A: Global MASTER-Net observations report
  70. Fermi trigger No 728706420: Global MASTER-Net observations report
  71. GRB 240204A: Swift detection of a burst
  72. IceCube-240204A - IceCube observation of a high-energy neutrino candidate track-like event
  73. GRB 240204A: Fermi GBM Final Real-time Localization
  74. GRB 230812B: Update on Bad Time Intervals for Fermi GBM data
  75. GRB 240129A: Fermi GBM Observation
  76. IPN triangulation of GRB 240125B (short)
  77. GRB 240129A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  78. Fermi GRB 240127A: Global MASTER-Net observations report
  79. GRB 240127A: Fermi GBM Final Real-time Localization
  80. GRB 240125B: Fermi GBM Final Localization
  81. GRB 240123B: Fermi GBM Observation
  82. GRB 240123A: Glowbug gamma-ray detection
  83. GRB 240123B: Swift/BAT-GUANO detection of a long burst
  84. GRB 240123A: GRBAlpha detection
  85. Fermi-LAT gamma-ray observations of IceCube-240123A
  86. Fermi/GBM trigger 727752941: BALROG analysis retraction
  87. GRB 240124A?: BALROG localization (Fermi Trigger 727752941 / GRB 240124066)
  88. Fermi GRB 240123B: Global MASTER-Net observations report
  89. Fermi GBM Sub-Threshold Detection of GRB 240123A
  90. GRB 240123B: Fermi GBM Final Real-time Localization
  91. IceCube-240123A - IceCube observation of a high-energy neutrino candidate track-like event
  92. Konus-Wind detection of GRB 240119A (short/hard)
  93. IPN triangulation of GRB 240119A (short)
  94. GRB 240119A: GECAM detection of a short burst
  95. GRB 240118C: GECAM-B detection of a long burst
  96. GRB 240119A: AstroSat CZTI detection of a short burst
  97. GRB 240118A: Mondy optical observations
  98. GRB 240118A: Swift-XRT afterglow detection
  99. GRB 240118C: Fermi GBM Observation
  100. Fermi GRB 240119A: Global MASTER-Net observations report

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