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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"

28226 results found.

  1. IceCube-240229A - IceCube observation of a high-energy neutrino candidate track-like event
  2. GRB 240225B: Swift ToO observations
  3. Konus-Wind detection of GRB 240225B (long)
  4. GRB 240229A: Fermi GBM Final Real-time Localization
  5. GRB 240225B: VLT/X-shooter redshift
  6. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  7. GRB 240225B: 3.6m DOT observation
  8. GRB 240226A: GRBAlpha detection
  9. GRB 240225B: Mondy afterglow observations
  10. GRB 240225B: Liverpool Telescope afterglow observations
  11. Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up
  12. IPN triangulation of GRB 240227A (short)
  13. GRB 240225B: Liverpool Telescope optical afterglow observations
  14. GRB 240225B: NOT optical observations
  15. GRB 240218A: CMO SAI NIR upper limit
  16. GRB 240227A: Fermi GBM Final Real-time Localization
  17. GRB 240225B: Nanshan/HMT optical afterglow detection
  18. GRB 240225B: CALET Gamma-Ray Burst Monitor detection
  19. GRB 240225B: Swift-XRT observations
  20. GRB 240226B: Fermi GBM Final Real-time Localization
  21. GRB 240225C: CALET Gamma-Ray Burst Monitor detection
  22. GRB 240225B: GOTO detection of a candidate optical afterglow
  23. GRB 240226A: Fermi GBM Final Real-time Localization
  24. Transient EPW20240219aa: REM optical/NIR upper limits
  25. GRB 240225C: GRBAlpha detection
  26. GRB 240222A: ATCA radio observations
  27. GRB 240225C: AstroSat CZTI detection
  28. GRB 240225B: AstroSat CZTI detection
  29. GRB 240225B: Tiled Swift observations
  30. GRB 240225B: MAXI/GSC detection
  31. GRB 240218A: VLA detection
  32. GRB 240225A: Swift/BAT-GUANO detection of a short burst
  33. GRB 240222A: GRBAlpha detection
  34. Transient EPW20240219aa: 7DT Optical Upper Limits
  35. Transient EPW20240219aa: upper limit in gamma-ray range from SPI-ACS/INTEGRAL observations
  36. Insight-HXMT/HE Sub-Threshold Detection of Transient EPW20240219aa
  37. Swift BAT Sub-Threshold Detection of EPW20240219aa
  38. Transient EPW20240219aa: Liverpool Telescope non-detection and limiting magnitude
  39. GRB 240222A: GECAM detection of a burst
  40. GRB 240222A: Swift-XRT refined Analysis
  41. GRB 240222A: Swift/UVOT Upper Limits
  42. Fermi GBM Sub-Threshold Detection of EPW20240219aa as a likely GRB
  43. EPW20240219aa is Likely a GRB Event
  44. GRB 240222A: REM optical and NIR early-time observations
  45. GRB 240222A: Swift detection of a burst
  46. GRB 240222A: Fermi GBM Final Real-time Localization
  47. GRB 240218A: MeerLICHT upper limits
  48. GRB 240216A: Glowbug gamma-ray detection
  49. GRB 240218A: LBT H-band detection
  50. GRB 240220A: Fermi GBM Final Real-time Localization
  51. Konus-Wind detection of GRB 240218A
  52. GRB 240218A: Swift-XRT refined Analysis
  53. GRB 240218A: VLT/X-shooter redshift of z = 6.782
  54. GRB 240218A: Fermi GBM Detection
  55. GRB 240216A: GRBAlpha detection
  56. GRB 240215B: GRBAlpha detection
  57. IPN triangulation of GRB 240209A
  58. GRB 240218A: VLT/FORS2 z-band detection
  59. GRB 240218A: Enhanced Swift-XRT position
  60. GRB 240218A: REM detection of a NIR afterglow candidate
  61. Gamma-ray flaring activity from the blazar 1ES 1959+650 observed by the Fermi-LAT
  62. GRB 240213A: GRBAlpha detection
  63. GRB 240218A : r-band upper limit from Observatoire de Haute-Provence
  64. GRB240218A: VLT/X-shooter upper limits
  65. GRB 240218A: Swift detection of a burst
  66. GRB 240215C: Fermi GBM Final Real-time Localization
  67. GRB 240215B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  68. GRB 240216A: Fermi GBM Final Real-time Localization
  69. GRB 240215A: Tiled Swift observations
  70. GRB 240215A: Swift/BAT-GUANO localization of a burst
  71. GRB 240213A: Glowbug gamma-ray detection
  72. GRB240209A: OHP/T193 detection of the GOTO afterglow candidate AT2024cew / GOTO24pw
  73. GRB 240209A: Wendelstein Optical Observations
  74. GRB 240128A: Further Swift-XRT observations
  75. GRB 240214A: Tiled Swift observations
  76. GRB 240214A/1H 0451-560: MAXI/GSC detection
  77. GRB 240213A: Fermi GBM Final Real-time Localization
  78. GRB 240209A: NOEMA non-detection of AT2024cew / GOTO24pw counterpart candidate
  79. GRB 240209A: NOT photometry of the AT2024cew / GOTO24pw counterpart candidate
  80. GRB 240209A: GOTO optical counterpart candidate
  81. Konus-Wind detection of GRB 240204A
  82. Konus-Wind detection of GRB 240205A (short)
  83. GRB 240209A: Fermi GBM Final Localization
  84. IPN triangulation of GRB 240205A (short)
  85. GRB 240205B: PRIME near infrared detection
  86. GRB 240205A (short): Glowbug gamma-ray detection
  87. GRB240204A: Swift/UVOT Upper Limits
  88. GRB 240205B: AstroSat CZTI detection
  89. Konus-Wind detection of GRB 240205B (long / very soft)
  90. GRB 240207A: Fermi GBM Final Real-time Localization
  91. Konus-Wind detection of GRB 240125A
  92. GRB 240205B: VLT/X-shooter redshift
  93. GRB 240205B: CALET Gamma-Ray Burst Monitor detection
  94. GRB 240205B: BOOTES-6 optical afterglow follow-up
  95. GRB 240205B: ATCA detection of radio counterpart
  96. GRB 240205B: REM detection of the optical/NIR afterglow
  97. GRB 240204A: AstroSat CZTI detection
  98. GRB 240204A: Mondy optical afterglow observations
  99. GRB 240204A : OHP/T193/T120 optical afterglow fading detection
  100. GRB 240205B: GECAM detection of a long burst

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