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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"

37775 results found.

  1. GRB 240215A: Fermi GBM Observation
  2. GRB 240216A: GRBAlpha detection
  3. GRB 240215B: GRBAlpha detection
  4. IPN triangulation of GRB 240209A
  5. Fermi trigger No 729914426: Global MASTER-Net observations report
  6. GRB 240218A: VLT/FORS2 z-band detection
  7. GRB 240218A: Enhanced Swift-XRT position
  8. GRB 240218A: REM detection of a NIR afterglow candidate
  9. Gamma-ray flaring activity from the blazar 1ES 1959+650 observed by the Fermi-LAT
  10. GRB 240213A: GRBAlpha detection
  11. GRB 240218A : r-band upper limit from Observatoire de Haute-Provence
  12. GRB240218A: VLT/X-shooter upper limits
  13. GRB 240218A: Swift detection of a burst
  14. GRB 240215C: Fermi GBM Final Real-time Localization
  15. GRB 240215B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  16. Fermi GRB 240216A: Global MASTER-Net observations report
  17. GRB 240216A: Fermi GBM Final Real-time Localization
  18. Fermi trigger No 729719508: Global MASTER-Net observations report
  19. GRB 240215A: Tiled Swift observations
  20. GRB 240215A: Swift/BAT-GUANO localization of a burst
  21. Fermi trigger No 729703985: Global MASTER-Net observations report
  22. Fermi trigger No 729650855: Global MASTER-Net observations report
  23. GRB 240209A: Classification of AT2024cew/GOTO24pw as Type Ia-pec supernova
  24. GRB 240209A: Fermi GBM observation
  25. GRB 240213A: Glowbug gamma-ray detection
  26. GRB240209A: OHP/T193 detection of the GOTO afterglow candidate AT2024cew / GOTO24pw
  27. GRB 240209A: Wendelstein Optical Observations
  28. GRB 240128A: Further Swift-XRT observations
  29. GRB 240214A: Tiled Swift observations
  30. GRB 240214A/1H 0451-560: MAXI/GSC detection
  31. GRB 240213A: BALROG localization (Fermi Trigger / GRB 240213841)
  32. Fermi GRB 240213A: Global MASTER-Net observations report
  33. GRB 240213A: Fermi GBM Final Real-time Localization
  34. GRB 240209A: NOEMA non-detection of AT2024cew / GOTO24pw counterpart candidate
  35. GRB 240209A: NOT photometry of the AT2024cew / GOTO24pw counterpart candidate
  36. GRB 240209A: GOTO optical counterpart candidate
  37. Konus-Wind detection of GRB 240204A
  38. Konus-Wind detection of GRB 240205A (short)
  39. GRB 240209A: Fermi GBM Final Localization
  40. Fermi trigger No 729152364: Global MASTER-Net observations report
  41. IPN triangulation of GRB 240205A (short)
  42. Fermi-LAT gamma-ray observations of IceCube-240204A
  43. GRB 240205B: PRIME near infrared detection
  44. GRB 240205A (short): Glowbug gamma-ray detection
  45. GRB240204A: Swift/UVOT Upper Limits
  46. GRB 240205B: AstroSat CZTI detection
  47. Fermi trigger No 729012023: Global MASTER-Net observations report
  48. GRB 240205B: Swift-BAT refined analysis
  49. Konus-Wind detection of GRB 240205B (long / very soft)
  50. GRB 240207A: Fermi GBM Final Real-time Localization
  51. Konus-Wind detection of GRB 240125A
  52. GRB 240205B: VLT/X-shooter redshift
  53. GRB 240205B: CALET Gamma-Ray Burst Monitor detection
  54. GRB 240205B: BOOTES-6 optical afterglow follow-up
  55. GRB 240205B: ATCA detection of radio counterpart
  56. GRB 240205B: REM detection of the optical/NIR afterglow
  57. GRB 240205B: Fermi GBM Observation
  58. GRB 240204A: AstroSat CZTI detection
  59. GRB 240204A: Mondy optical afterglow observations
  60. GRB 240204A : OHP/T193/T120 optical afterglow fading detection
  61. GRB 240205B: GECAM detection of a long burst
  62. GRB 240204A: Swift-BAT refined analysis
  63. GRB 240205B: Skynet Optical Afterglow Observations
  64. GRB 240205B: BOOTES-7 optical afterglow follow-up
  65. Fermi trigger No 728749569: Global MASTER-Net observations report
  66. GRB 240205B: MASTER OT J232550.14-550704.6 counterpart detection
  67. GRB 240205B: Swift detection of a burst
  68. GRB 240205B: Fermi GBM Final Real-time Localization
  69. GRB 240204A: Fermi GBM Observation
  70. GRB 240205A: Fermi GBM Final Real-time Localization
  71. GRB 240204a: Liverpool Telescope optical afterglow detection
  72. GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
  73. Fermi Gamma-ray Burst Monitor trigger 728740048/240204491 is not a GRB
  74. Fermi trigger No 728796365: Global MASTER-Net observations report
  75. GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
  76. GRB 240204A: Montarrenti Observatory optical observations
  77. GRB 240204A: Enhanced Swift-XRT position
  78. GRB 240204A: Mondy optical afterglow candidate
  79. Fermi Gamma-ray Burst Monitor trigger 728706420/240204102 is not a GRB
  80. Fermi GRB 240204A: Global MASTER-Net observations report
  81. Fermi trigger No 728706420: Global MASTER-Net observations report
  82. GRB 240204A: Swift detection of a burst
  83. IceCube-240204A - IceCube observation of a high-energy neutrino candidate track-like event
  84. GRB 240204A: Fermi GBM Final Real-time Localization
  85. GRB 230812B: Update on Bad Time Intervals for Fermi GBM data
  86. Konus-Wind detection of GRB 240124B
  87. Konus-Wind detection of GRB 240123C
  88. IPN triangulation of GRB 240124B
  89. GRB 240201A: AstroSat CZTI detection
  90. GRB 240129A: Fermi GBM Observation
  91. IPN triangulation of GRB 240125B (short)
  92. GRB 240129A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  93. IPN triangulation of GRB 240125A (short)
  94. GRB 240128A: Glowbug gamma-ray detection
  95. GRB 240128A: Swift-XRT observations
  96. GRB 240128A: GRBAlpha detection
  97. GRB 240128A: Tiled Swift observations
  98. GRB 240128A: CALET Gamma-Ray Burst Monitor detection
  99. GRB 240128A: MAXI/GSC detection
  100. GRB 240125A: GRBAlpha detection

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