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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"

11539 results found.

  1. GRB 240713A: JinShan optical upper limits
  2. GRB 240713A: OHP/T120 optical upper limit
  3. GRB240713A: X-ray follow-up observation with EP-FXT
  4. Fermi Sub-threshold Observation of GRB240713A
  5. Fermi Gamma-ray Burst Monitor trigger 742413075/240711744 is not a GRB
  6. GRB 240711A: Fermi GBM Final Real-time Localization
  7. Fermi trigger No 742405878: Global MASTER-Net observations report
  8. Fermi trigger No 742317942: Global MASTER-Net observations report
  9. Fermi GRB 240710A: Global MASTER-Net observations report
  10. GRB 240710A: Fermi GBM Final Real-time Localization
  11. Fermi Gamma-ray Burst Monitor trigger 741911057/240705933 is not a GRB
  12. GRB 240705A: Fermi GBM Final Real-time Localization
  13. IPN triangulation of GRB 240628B (short)
  14. IPN triangulation of GRB 240627A
  15. GRB 240619A: Host galaxy redshift from VLT/X-shooter
  16. The first three GRBs detected by SVOM: GRB 240627B, GRB 240629A and GRB 240702A
  17. GRB 240702A: BALROG localization (Fermi Trigger / GRB 240702885)
  18. Fermi GRB 240702A: Global MASTER-Net observations report
  19. GRB 240702A: Fermi GBM Final Real-time Localization
  20. Fermi Gamma-ray Burst Monitor trigger 741448122/240630575 is not a GRB
  21. Fermi trigger No 741448122: Global MASTER-Net observations report
  22. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  23. Fermi trigger No 741356809: Global MASTER-Net observations report
  24. Fermi GRB 240629A: Global MASTER-Net observations report
  25. Fermi Gamma-ray Burst Monitor trigger 741362867/240629589 is not a GRB
  26. Fermi Gamma-ray Burst Monitor trigger 741288821/240628732 is not a GRB
  27. GRB 240629A: BALROG localization (Fermi Trigger 741372837 / GRB 240629704)
  28. GRB 240629A: Fermi GBM Final Real-time Localization
  29. Fermi Gamma-ray Burst Monitor trigger 741356809/240629519 is not a GRB
  30. Fermi trigger No 741296200: Global MASTER-Net observations report
  31. Fermi trigger No 741251380: Global MASTER-Net observations report
  32. IPN triangulation of GRB 240619C
  33. GRB 240628A: BALROG localization (Fermi Trigger 741288821 / GRB 240628732)
  34. GRB 240615A: SAI CMO J- band observations
  35. Fermi trigger No 741211696: Global MASTER-Net observations report
  36. Konus-Wind detection of GRB 240619A
  37. Fermi GRB 240625B: Global MASTER-Net observations report
  38. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  39. GRB 240625B: Fermi GBM Final Real-time Localization
  40. GRB 240625A: Fermi GBM Observation
  41. GRB 240624B: GRBAlpha detection
  42. GRB 240625A: Fermi GBM Final Real-time Localization
  43. GRB240624A: Fermi GBM Observation
  44. GRB240615A: Gemini-North observations of the BAT and XRT positions
  45. Fermi GRB 240624A: Global MASTER-Net observations report
  46. GRB 240624B: Fermi GBM Final Real-time Localization
  47. Fermi trigger No 740949590: Global MASTER-Net observations report
  48. GRB240615A: Gemini-North observations of the BAT and XRT positions
  49. GRB 240624A: Fermi GBM Final Real-time Localization
  50. GRB 240619A: J-band detection with WINTER
  51. Fermi trigger No 740744838: Global MASTER-Net observations report
  52. IPN triangulation of GRB 240615A (short)
  53. X-ray transient EP240618a: Fermi/GBM non-detection
  54. GRB 240619A: GRBAlpha detection
  55. EP240617a: tentative Swift/XRT detection of the afterglow
  56. GRB 240619A: Swift-XRT probable afterglow detection
  57. GRB 240619A: Swift ToO observations
  58. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  59. GRB 240619C: NuSTAR automated detection of the GRB
  60. GRB 240619A: Fermi GBM Observation
  61. Fermi GBM Sub-Threshold Detection of GRB 240619C
  62. GRB 240619A: GOTO candidate optical afterglow
  63. GRB 240615A: NOT optical observations
  64. Fermi trigger No 740474239: Global MASTER-Net observations report
  65. Fermi GRB 240619A: Global MASTER-Net observations report
  66. Fermi Gamma-ray Burst Monitor trigger 740474239/240619304 is not a GRB
  67. GRB 240619B: Fermi GBM Final Real-time Localization
  68. Fermi trigger No 740430582: Global MASTER-Net observations report
  69. GRB240615A: 1.3m DFOT optical upper limit
  70. GRB 240619A: BALROG localization (Fermi Trigger 740461416 / GRB 240619155)
  71. GRB 240619A: Fermi GBM Final Real-time Localization
  72. EP240617a is likely a GRB event
  73. GRB 240615A: Fermi GBM Observation
  74. GRB 240615A: GECAM detection
  75. GRB 240615A: FLWO-1.2m optical upper limits
  76. Fermi trigger No 740221779: Global MASTER-Net observations report
  77. Fermi GRB 240616A: Global MASTER-Net observations report
  78. Konus-Wind detection of GRB 240615A (short/hard)
  79. GRB 240615A: GOTO optical upper limits
  80. Fermi trigger No 740166710: Global MASTER-Net observations report
  81. GRB 240616A: Fermi GBM Final Real-time Localization
  82. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  83. GRB 240615A: Fermi GBM Final Real-time Localization
  84. GRB 240603A: VZLUSAT-2 detection
  85. GRB 240612A: GRBAlpha detection
  86. GRB 240613A: Fermi GBM Final Real-time Localization
  87. Fermi GRB 240612B: Global MASTER-Net observations report
  88. Fermi GRB 240612A: Global MASTER-Net observations report
  89. GRB 240612B: Fermi GBM Final Real-time Localization
  90. GRB 240612A: Fermi GBM Final Real-time Localization
  91. GRB 240607A: GECAM detection of a bright long burst
  92. Fermi GRB 240611A: Global MASTER-Net observations report
  93. Konus-Wind detection of GRB 240607A
  94. GRB 240611A: Fermi GBM Final Real-time Localization
  95. Fermi GRB 240610A: Global MASTER-Net observations report
  96. GRB 240610A: Fermi GBM Final Real-time Localization
  97. IPN triangulation of GRB 240607A
  98. Fermi Gamma-ray Burst Monitor trigger 739632045/240609556 is not a GRB
  99. Fermi trigger No 739632045: Global MASTER-Net observations report
  100. Fermi GRB 240608A: Global MASTER-Net observations report

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