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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"

32767 results found.

  1. Transient EPW20240219aa: Mondy optical observations
  2. Transient EPW20240219aa: upper limit in gamma-ray range from SPI-ACS/INTEGRAL observations
  3. Insight-HXMT/HE Sub-Threshold Detection of Transient EPW20240219aa
  4. Swift BAT Sub-Threshold Detection of EPW20240219aa
  5. Transient EPW20240219aa: Liverpool Telescope non-detection and limiting magnitude
  6. GRB 240222A: GECAM detection of a burst
  7. GRB 240222A: Swift-BAT refined analysis
  8. GRB 240222A: Fermi GBM Observation
  9. GRB 240222A: Swift/UVOT Upper Limits
  10. Fermi GBM Sub-Threshold Detection of EPW20240219aa as a likely GRB
  11. Swift GRB 240222A: Global MASTER-Net observations report
  12. Fermi GRB 240222A: Global MASTER-Net observations report
  13. GRB 240222A: REM optical and NIR early-time observations
  14. GRB 240218A: MeerLICHT upper limits
  15. GRB 240216A: Glowbug gamma-ray detection
  16. GRB 240215B: Fermi GBM Observation
  17. GRB 240218A: LBT H-band detection
  18. GRB 240218A: Swift-BAT refined analysis
  19. Fermi GRB 240220A: Global MASTER-Net observations report
  20. Konus-Wind detection of GRB 240218A
  21. GRB 240218A: VLT/X-shooter redshift of z = 6.782
  22. GRB 240218A: Fermi GBM Detection
  23. GRB 240215A: Fermi GBM Observation
  24. GRB 240216A: GRBAlpha detection
  25. GRB 240215B: GRBAlpha detection
  26. IPN triangulation of GRB 240209A
  27. GRB 240218A: VLT/FORS2 z-band detection
  28. GRB 240218A: REM detection of a NIR afterglow candidate
  29. GRB 240213A: GRBAlpha detection
  30. GRB 240218A : r-band upper limit from Observatoire de Haute-Provence
  31. GRB240218A: VLT/X-shooter upper limits
  32. Fermi GRB 240216A: Global MASTER-Net observations report
  33. GRB 240215A: Tiled Swift observations
  34. GRB 240215A: Swift/BAT-GUANO localization of a burst
  35. GRB 240209A: Classification of AT2024cew/GOTO24pw as Type Ia-pec supernova
  36. GRB 240209A: Fermi GBM observation
  37. GRB 240213A: Glowbug gamma-ray detection
  38. GRB240209A: OHP/T193 detection of the GOTO afterglow candidate AT2024cew / GOTO24pw
  39. GRB 240209A: Wendelstein Optical Observations
  40. GRB 240128A: Further Swift-XRT observations
  41. GRB 240214A: Tiled Swift observations
  42. Fermi GRB 240213A: Global MASTER-Net observations report
  43. GRB 240209A: NOEMA non-detection of AT2024cew / GOTO24pw counterpart candidate
  44. GRB 240209A: NOT photometry of the AT2024cew / GOTO24pw counterpart candidate
  45. GRB 240209A: GOTO optical counterpart candidate
  46. Konus-Wind detection of GRB 240204A
  47. Konus-Wind detection of GRB 240205A (short)
  48. IPN triangulation of GRB 240205A (short)
  49. Fermi-LAT gamma-ray observations of IceCube-240204A
  50. GRB 240205B: PRIME near infrared detection
  51. GRB 240205A (short): Glowbug gamma-ray detection
  52. GRB240204A: Swift/UVOT Upper Limits
  53. GRB 240205B: AstroSat CZTI detection
  54. GRB 240205B: Swift-BAT refined analysis
  55. Konus-Wind detection of GRB 240205B (long / very soft)
  56. Konus-Wind detection of GRB 240125A
  57. GRB 240205B: VLT/X-shooter redshift
  58. GRB 240205B: CALET Gamma-Ray Burst Monitor detection
  59. GRB 240205B: ATCA detection of radio counterpart
  60. GRB 240205B: REM detection of the optical/NIR afterglow
  61. GRB 240205B: Fermi GBM Observation
  62. GRB 240204A: AstroSat CZTI detection
  63. GRB 240204A: Mondy optical afterglow observations
  64. GRB 240204A : OHP/T193/T120 optical afterglow fading detection
  65. GRB 240205B: GECAM detection of a long burst
  66. GRB 240204A: Swift-BAT refined analysis
  67. GRB 240205B: Skynet Optical Afterglow Observations
  68. GRB 240205B: MASTER OT J232550.14-550704.6 counterpart detection
  69. GRB 240204A: Fermi GBM Observation
  70. GRB 240204a: Liverpool Telescope optical afterglow detection
  71. GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
  72. IceCube-240204A: Upper limits from a search for additional neutrino events in IceCube
  73. GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
  74. GRB 240204A: Montarrenti Observatory optical observations
  75. GRB 240204A: Mondy optical afterglow candidate
  76. Fermi GRB 240204A: Global MASTER-Net observations report
  77. GRB 240204A: Swift detection of a burst
  78. GRB 230812B: Update on Bad Time Intervals for Fermi GBM data
  79. Konus-Wind detection of GRB 240124B
  80. Konus-Wind detection of GRB 240123C
  81. IPN triangulation of GRB 240124B
  82. GRB 240129A: Fermi GBM Observation
  83. IPN triangulation of GRB 240125B (short)
  84. IPN triangulation of GRB 240125A (short)
  85. GRB 240128A: Glowbug gamma-ray detection
  86. GRB 240128A: GRBAlpha detection
  87. GRB 240128A: Tiled Swift observations
  88. GRB 240128A: CALET Gamma-Ray Burst Monitor detection
  89. GRB 240125A: GRBAlpha detection
  90. Fermi GRB 240127A: Global MASTER-Net observations report
  91. GRB 240123C: GRBAlpha detection
  92. GRB 240122A: ATCA detection of radio counterpart
  93. IceCube-240123A: Upper limits from a search for additional neutrino events in IceCube
  94. GRB 240125A: CALET Gamma-Ray Burst Monitor detection
  95. GRB 240125A: AstroSat CZTI detection of a short burst
  96. GRB 240123C: AstroSat CZTI detection
  97. GRB240122A: PRIME near infrared detection
  98. GRB 240123B: Fermi GBM Observation
  99. GRB 240123A: Glowbug gamma-ray detection
  100. GRB 240123B: Swift/BAT-GUANO detection of a long burst

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