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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').
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"

28059 results found.

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

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