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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"

38346 results found.

  1. GRB 240213A: Glowbug gamma-ray detection
  2. GRB240209A: OHP/T193 detection of the GOTO afterglow candidate AT2024cew / GOTO24pw
  3. GRB 240209A: Wendelstein Optical Observations
  4. GRB 240128A: Further Swift-XRT observations
  5. GRB 240214A: Tiled Swift observations
  6. GRB 240214A/1H 0451-560: MAXI/GSC detection
  7. GRB 240213A: BALROG localization (Fermi Trigger / GRB 240213841)
  8. Fermi GRB 240213A: Global MASTER-Net observations report
  9. GRB 240213A: Fermi GBM Final Real-time Localization
  10. GRB 240209A: NOEMA non-detection of AT2024cew / GOTO24pw counterpart candidate
  11. GRB 240209A: NOT photometry of the AT2024cew / GOTO24pw counterpart candidate
  12. GRB 240209A: GOTO optical counterpart candidate
  13. Konus-Wind detection of GRB 240204A
  14. Konus-Wind detection of GRB 240205A (short)
  15. GRB 240209A: Fermi GBM Final Localization
  16. Fermi trigger No 729152364: Global MASTER-Net observations report
  17. IPN triangulation of GRB 240205A (short)
  18. Fermi-LAT gamma-ray observations of IceCube-240204A
  19. GRB 240205B: PRIME near infrared detection
  20. GRB 240205A (short): Glowbug gamma-ray detection
  21. GRB240204A: Swift/UVOT Upper Limits
  22. GRB 240205B: AstroSat CZTI detection
  23. Fermi trigger No 729012023: Global MASTER-Net observations report
  24. GRB 240205B: Swift-BAT refined analysis
  25. Konus-Wind detection of GRB 240205B (long / very soft)
  26. GRB 240207A: Fermi GBM Final Real-time Localization
  27. Konus-Wind detection of GRB 240125A
  28. GRB 240205B: VLT/X-shooter redshift
  29. GRB 240205B: CALET Gamma-Ray Burst Monitor detection
  30. GRB 240205B: BOOTES-6 optical afterglow follow-up
  31. GRB 240205B: ATCA detection of radio counterpart
  32. GRB 240205B: REM detection of the optical/NIR afterglow
  33. GRB 240205B: Fermi GBM Observation
  34. GRB 240204A: AstroSat CZTI detection
  35. GRB 240204A: Mondy optical afterglow observations
  36. GRB 240204A : OHP/T193/T120 optical afterglow fading detection
  37. GRB 240205B: GECAM detection of a long burst
  38. GRB 240204A: Swift-BAT refined analysis
  39. GRB 240205B: Skynet Optical Afterglow Observations
  40. GRB 240205B: BOOTES-7 optical afterglow follow-up
  41. Fermi trigger No 728749569: Global MASTER-Net observations report
  42. GRB 240205B: MASTER OT J232550.14-550704.6 counterpart detection
  43. GRB 240205B: Swift detection of a burst
  44. GRB 240205B: Fermi GBM Final Real-time Localization
  45. Swift GRB240205.93: Global MASTER-Net observations report
  46. GRB 240204A: Fermi GBM Observation
  47. GRB 240205A: Fermi GBM Final Real-time Localization
  48. GRB 240204a: Liverpool Telescope optical afterglow detection
  49. GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
  50. Fermi Gamma-ray Burst Monitor trigger 728740048/240204491 is not a GRB
  51. Fermi trigger No 728796365: Global MASTER-Net observations report
  52. GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
  53. GRB 240204A: Montarrenti Observatory optical observations
  54. GRB 240204A: Enhanced Swift-XRT position
  55. GRB 240204A: Mondy optical afterglow candidate
  56. Fermi Gamma-ray Burst Monitor trigger 728706420/240204102 is not a GRB
  57. Fermi GRB 240204A: Global MASTER-Net observations report
  58. Fermi trigger No 728706420: Global MASTER-Net observations report
  59. GRB 240204A: Swift detection of a burst
  60. GRB 240204A: Fermi GBM Final Real-time Localization
  61. IceCube Alert 240204.38: Global MASTER-Net observations report
  62. GRB 230812B: Update on Bad Time Intervals for Fermi GBM data
  63. Konus-Wind detection of GRB 240124B
  64. Konus-Wind detection of GRB 240123C
  65. IPN triangulation of GRB 240124B
  66. GRB 240201A: AstroSat CZTI detection
  67. GRB 240129A: Fermi GBM Observation
  68. IPN triangulation of GRB 240125B (short)
  69. GRB 240129A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  70. IPN triangulation of GRB 240125A (short)
  71. GRB 240128A: Glowbug gamma-ray detection
  72. GRB 240128A: Swift-XRT observations
  73. GRB 240128A: GRBAlpha detection
  74. GRB 240128A: Tiled Swift observations
  75. GRB 240128A: CALET Gamma-Ray Burst Monitor detection
  76. GRB 240128A: MAXI/GSC detection
  77. GRB 240125A: GRBAlpha detection
  78. Fermi GRB 240127A: Global MASTER-Net observations report
  79. GRB 240123C: GRBAlpha detection
  80. GRB 240122A: ATCA detection of radio counterpart
  81. GRB 240127A: Fermi GBM Final Real-time Localization
  82. GRB 240125A: CALET Gamma-Ray Burst Monitor detection
  83. GRB 240125A: AstroSat CZTI detection of a short burst
  84. GRB 240124B: AstroSat CZTI detection
  85. GRB 240123C: AstroSat CZTI detection
  86. GRB 240125B: Fermi GBM Final Localization
  87. GRB240122A: PRIME near infrared detection
  88. GRB 240123B: Fermi GBM Observation
  89. GRB 240123A: Glowbug gamma-ray detection
  90. GRB 240125A (short): Glowbug gamma-ray detection
  91. GRB 240123B: Swift/BAT-GUANO detection of a long burst
  92. GRB 240123A: GRBAlpha detection
  93. IPN triangulation of GRB 240123C (short)
  94. GRB 240123A: further SAO RAS optical observations
  95. GRB 240122B: CALET Gamma-Ray Burst Monitor detection
  96. GRB 240123A: Swift-BAT refined analysis
  97. IceCube Alert 240123.48: Global MASTER-Net observations report
  98. GRB 240123A: Mondy continued optical observations and the PL decay index
  99. GRB 240123A: SAO RAS optical observations
  100. GRB 240123A : MITSuME Akeno optical afterglow candidate detection

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