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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').
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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"

28056 results found.

  1. GRB 190114C: GROND detection of the afterglow
  2. GRB 190114C: OASDG optical observations
  3. GRB 190114B: Mondy optical afterglow detection
  4. GRB 190114B: BOOTES-4/MET optical afterglow detection
  5. GRB 190114C: MASTER 4-polarizations filters OT detection
  6. GRB 190114B: Enhanced Swift-XRT position
  7. GRB 190114C: MASTER afterglow Detection
  8. INTEGRAL observation of IceCube-190104A
  9. GRB 190114C: Swift detection of a very bright burst with a bright optical counterpart
  10. GRB 190114B: Swift detection of a burst
  11. GRB 190114A: Swift-BAT refined analysis
  12. GRB 190103B: Swift/UVOT Upper Limits
  13. GRB 190114A: Swift-XRT refined Analysis
  14. GRB 190114A: GROND detection of the afterglow
  15. GRB 190114A: Enhanced Swift-XRT position
  16. GRB 190114A: Possible UVOT Detection
  17. GRB 190114A: Swift detection of a burst
  18. GRB 190110A:Insight-HXMT/HE detection
  19. GRB 190110A, Swift-BAT refined analysis
  20. Correction to GCN Circular 23663: GRB 190109A: Swift UVOT Upper Limits
  21. GRB 190110A: Fermi GBM detection
  22. GRB 190109B: Fermi GBM observation
  23. GRB 190109B: Swift/UVOT Upper Limits
  24. GRB 190109A: Swift/UVOT Upper Limits
  25. GRB 190109B: Swift-XRT refined Analysis
  26. GRB 190106A: optical observations, possible jet break detection
  27. GRB 190106A: Liverpool Telescope observations
  28. GRB 190109B: Swift-BAT refined analysis
  29. GRB 190109B: COATLI Optical Observations
  30. GRB 190109B: Mondy optical upper limit
  31. GRB 190109A: Swift-BAT refined analysis
  32. GRB 190109B: Enhanced Swift-XRT position
  33. GRB 190109B: Swift-XRT observations
  34. INTEGRAL Weak#8189: AROMA-N Optical Observation
  35. GRB 190109B: Swift detection of a burst
  36. CALET Gamma-Ray Burst Monitor: Policy change in the GCN circulars
  37. IPN triangulation of GRB 190103A (long)
  38. GRB 190109A: Swift-XRT refined Analysis
  39. GRB 190109A: Enhanced Swift-XRT position
  40. GRB 190109A: Swift detection of a burst
  41. IceCube-190104A: Swift-XRT observations
  42. GRB 190106A: NEXT-0.6m and Xinglong-2.16m photometric single powerlaw decay
  43. GRB 190106A: Swift-XRT refined Analysis
  44. GRB 190106A: OASDG optical observations
  45. GRB 190106A: Swift/UVOT Detection
  46. GRB 190106A: Swift-BAT refined analysis
  47. GRB 190106A: Bassano Bresciano Observatory optical detection
  48. Fermi GBM Observations of IceCube-190104A
  49. GRB 190106A : TSHAO optical observations
  50. GRB 190106A: Enhanced Swift-XRT position
  51. GRB 190106A: GMG detection
  52. GRB 190106A: Swift detection of a burst with an optical counterpart
  53. SWIFT GRB190106.57 Global MASTER-Net OT detection
  54. Search for counterpart to IceCube-190104A with ANTARES
  55. IceCube-190104A: MASTER optical observation
  56. GRB 190103A: AstroSat CZTI detection
  57. Fermi LAT Gamma-ray Observations of IceCube-190104A
  58. GRB 190103B: Bassano Bresciano observatory upper limit
  59. GRB 190103B: Swift-BAT refined analysis
  60. GRB 190103B: Swift-XRT refined Analysis
  61. GRB 190103B: Enhanced Swift-XRT position
  62. GRB 190103B: Swift detection of a burst
  63. GRB 181231A: Fermi GBM detection
  64. GRB 181228A: Mondy and AbAO optical upper limits
  65. GRB 181225A: further Swift-XRT observations
  66. GRB 181228A: possible NOT optical detection
  67. GRB 181228A: Xinglong-2.16m optical upper limit
  68. GRB 181227A: Global MASTER Net oprtical inspection
  69. Swift Trigger 880127 is not a GRB
  70. GRB 181228A: Swift-XRT refined Analysis
  71. GRB 181228A: Swift-BAT refined analysis
  72. GRB 181222B: Swift follow-up observations of MASTER optical transient J204928.79+245744.0
  73. GRB 181228A: Swift/UVOT Upper Limits
  74. GRB 181228A: TSHAO optical upper limit
  75. GRB 181228A: Fermi GBM observation
  76. GRB 181228A: Global MASTER Net OT detection
  77. GRB 181228A: REM NIR detection
  78. GRB 181228A: Enhanced Swift-XRT position
  79. GRB 181225A: KAIT Follow-Up Observations with Upper Limit
  80. GRB 181228A: Swift detection of a burst
  81. GRB 181227A: Fermi GBM detection
  82. GRB 181225A: Swift observations and X-ray candidate afterglow
  83. GRB 181225A: Fermi GBM detection
  84. GRB 181225A: Fermi-LAT Detection
  85. GRB 181224A: Swift-BAT refined analysis
  86. GRB 181224A: Swift detection of a burst
  87. GRB 181222B : Fermi GBM detection
  88. Swift Trigger 878504 is not astrophysical
  89. GRB 181222A: Fermi GBM observation
  90. GRB 181222A: MAXI/GSC detection
  91. GRB 181217A: Insight-HXMT/HE detection
  92. GRB 181213A: Swift/UVOT Observations
  93. GRB 181213A: Mondy optical observations
  94. GRB 181213A: continued TSHAO optical observations
  95. GRB 181213A:Insight-HXMT/HE detection
  96. GRB 181212A:Insight-HXMT/HE detection
  97. GRB 181213A: AbAO optical observations
  98. GRB 181213A: HMM-0.5m, NEXT-0.6m, CNEOST-1m optical observations
  99. GRB 181213A: NOT optical observations
  100. GRB 181213A: Swift-XRT refined Analysis

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