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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"

45799 results found.

  1. GRB 240225B: NOT optical observations
  2. GRB 240218A: CMO SAI NIR upper limit
  3. Fermi GRB 240226A: Global MASTER-Net observations report
  4. Swift-BAT triggers 1217733 - 1217736 are not astrophysical events
  5. Swift-BAT triggers 1217729-1217732 are not astrophysical
  6. GRB 240227A: Fermi GBM Final Real-time Localization
  7. Fermi Gamma-ray Burst Monitor trigger 730618809/240226236 is not a GRB
  8. GRB 240225B: Nanshan/HMT optical afterglow detection
  9. GRB 240225B: CALET Gamma-Ray Burst Monitor detection
  10. GRB 240225B: Swift-XRT observations
  11. GRB 240226B: Fermi GBM Final Real-time Localization
  12. Transient EPW20240219aa: Kp-band imaging observations with NIRES
  13. Transient EPW20240219aa: J-band upper limits from WINTER
  14. GRB 240225C: CALET Gamma-Ray Burst Monitor detection
  15. GRB 240225B: GOTO detection of a candidate optical afterglow
  16. GRB 240226A: Fermi GBM Final Real-time Localization
  17. Transient EPW20240219aa: REM optical/NIR upper limits
  18. GRB 240225C: GRBAlpha detection
  19. GRB 240222A: ATCA radio observations
  20. Fermi trigger No 730618809: Global MASTER-Net observations report
  21. GRB 240225C: AstroSat CZTI detection
  22. GRB 240225B: AstroSat CZTI detection
  23. GRB 240225B: Tiled Swift observations
  24. GRB 240225B: MAXI/GSC detection
  25. Transient EPW20240219aa: Xinglong-2.16m optical upper limit
  26. GRB 240218A: VLA detection
  27. GRB 240225A: Swift/BAT-GUANO detection of a short burst
  28. GRB 240222A: GRBAlpha detection
  29. Transient EPW20240219aa: GECKO: LOAO Optical Upper Limits
  30. Transient EPW20240219aa: 7DT Optical Upper Limits
  31. Swift-BAT triggers 1217218-1217222 are not astrophysical
  32. VLA X-band observation of EPW20240219aa
  33. Transient EPW20240219aa: Mondy optical observations
  34. Transient EPW20240219aa: upper limit in gamma-ray range from SPI-ACS/INTEGRAL observations
  35. Insight-HXMT/HE Sub-Threshold Detection of Transient EPW20240219aa
  36. Swift BAT Sub-Threshold Detection of EPW20240219aa
  37. Transient EPW20240219aa: Liverpool Telescope non-detection and limiting magnitude
  38. GRB 240222A: GECAM detection of a burst
  39. GRB 240222A: Swift-BAT refined analysis
  40. GRB 240222A: Swift-XRT refined Analysis
  41. Swift-BAT triggers 1216907-1216911 are not astrophysical
  42. GRB 240222A: Fermi GBM Observation
  43. GRB 240222A: Swift/UVOT Upper Limits
  44. Fermi GBM Sub-Threshold Detection of EPW20240219aa as a likely GRB
  45. Swift GRB 240222A: Global MASTER-Net observations report
  46. Fermi GRB 240222A: Global MASTER-Net observations report
  47. EPW20240219aa is Likely a GRB Event
  48. Swift Trigger 1216864 is not an astrophysical event
  49. GRB 240222A: REM optical and NIR early-time observations
  50. GRB 240222A: Swift detection of a burst
  51. GRB 240222A: Fermi GBM Final Real-time Localization
  52. Swift-BAT triggers 1216751 and 1216753 are not astrophysical events
  53. Swift-BAT triggers 1216743-1216748 are not astrophysical
  54. Swift GRB240221.92: Global MASTER-Net observations report
  55. GRB 240218A: MeerLICHT upper limits
  56. GRB 240216A: Glowbug gamma-ray detection
  57. GRB 240215B: Fermi GBM Observation
  58. GRB 240218A: LBT H-band detection
  59. GRB 240218A: Swift-BAT refined analysis
  60. Fermi GRB 240220A: Global MASTER-Net observations report
  61. GRB 240220A: Fermi GBM Final Real-time Localization
  62. Konus-Wind detection of GRB 240218A
  63. GRB 240218A: Swift-XRT refined Analysis
  64. GRB 240218A: VLT/X-shooter redshift of z = 6.782
  65. GRB 240218A: Fermi GBM Detection
  66. GRB 240215A: Fermi GBM Observation
  67. GRB 240216A: GRBAlpha detection
  68. GRB 240215B: GRBAlpha detection
  69. IPN triangulation of GRB 240209A
  70. Fermi trigger No 729914426: Global MASTER-Net observations report
  71. GRB 240218A: VLT/FORS2 z-band detection
  72. GRB 240218A: Enhanced Swift-XRT position
  73. GRB 240218A: REM detection of a NIR afterglow candidate
  74. Gamma-ray flaring activity from the blazar 1ES 1959+650 observed by the Fermi-LAT
  75. GRB 240213A: GRBAlpha detection
  76. GRB 240218A : r-band upper limit from Observatoire de Haute-Provence
  77. GRB240218A: VLT/X-shooter upper limits
  78. GRB 240218A: Swift detection of a burst
  79. Swift GRB240218.08: Global MASTER-Net observations report
  80. GRB 240215C: Fermi GBM Final Real-time Localization
  81. GRB 240215B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  82. Fermi GRB 240216A: Global MASTER-Net observations report
  83. Swift Triggers 12156887-1215690 are not astrophysical events.
  84. GRB 240216A: Fermi GBM Final Real-time Localization
  85. Fermi trigger No 729719508: Global MASTER-Net observations report
  86. GRB 240215A: Tiled Swift observations
  87. GRB 240215A: Swift/BAT-GUANO localization of a burst
  88. Fermi trigger No 729703985: Global MASTER-Net observations report
  89. Fermi trigger No 729650855: Global MASTER-Net observations report
  90. GRB 240209A: Classification of AT2024cew/GOTO24pw as Type Ia-pec supernova
  91. GRB 240209A: Fermi GBM observation
  92. GRB 240213A: Glowbug gamma-ray detection
  93. The AGILE satellite ceased operations and re-entered today into the atmosphere
  94. The AGILE satellite ceased operations and re-entered today into the atmosphere
  95. GRB240209A: OHP/T193 detection of the GOTO afterglow candidate AT2024cew / GOTO24pw
  96. GRB 240209A: Wendelstein Optical Observations
  97. GRB 240128A: Further Swift-XRT observations
  98. GRB 240214A: Tiled Swift observations
  99. GRB 240214A/1H 0451-560: MAXI/GSC detection
  100. GRB 240213A: BALROG localization (Fermi Trigger / GRB 240213841)

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