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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"

11059 results found.

  1. GRB 240828A: SAO RAS AS-500(2) optical observations
  2. Fermi trigger No 746882332: Global MASTER-Net observations report
  3. GRB 240825A: TSHAO Optical Upper Limit
  4. GRB 240829B: GRBAlpha detection
  5. Fermi trigger No 746816563: Global MASTER-Net observations report
  6. GRB 240831A: Fermi GBM Final Real-time Localization
  7. GRB 240825A: SOAR observations
  8. Fermi trigger No 746684112: Global MASTER-Net observations report
  9. GRB 240828A: SAO RAS optical observations
  10. Fermi trigger No 746587425: Global MASTER-Net observations report
  11. GRB 240829B: Fermi GBM Final Localization
  12. GRB 240828A: Fermi GBM Observation
  13. GRB 240629A: First GRB Detected by BurstCube
  14. GRB 240828A: KAIT Optical Afterglow Candidate
  15. GRB 240825A: SVOM/VT optical detection
  16. GRB 240828A: Swift-XRT afterglow detection
  17. GRB 240825A: further SAO RAS optical observations
  18. GRB 240828A: Fermi-LAT detection
  19. GRB 240828A: Tiled Swift observations
  20. GRB 240828A: AstroSat CZTI detection of a long burst
  21. Fermi GRB 240828A: Bassano Bresciano Observatory upper limit
  22. GRB 240825A: Upper limits from a neutrino search with IceCube
  23. Fermi GRB 240828A: Global MASTER-Net observations report
  24. Fermi trigger No 746438824: Global MASTER-Net observations report
  25. GRB 240828A: Fermi GBM Final Real-time Localization
  26. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  27. GRB 240825A: GECAM detection
  28. GRB 240825A: SAO RAS optical observations
  29. GRB 240825A: TNG optical photometry and spectroscopy
  30. GRB 240824B: Ondrejov D50 optical limit
  31. GRB 240825A: KAIT optical observations
  32. GRB 240825A: PRIME near-infrared detection
  33. Konus-Wind detection of GRB 240825A (bright/long)
  34. GRB 240825A: Fermi GBM Observation
  35. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  36. GRB 240825A: AKO Optical Follow-Up Observations
  37. GRB 240825A: AstroSat CZTI detection of the long bright burst
  38. SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
  39. GRB 240825A: REM detection of the optical/NIR afterglow
  40. GRB 240825A: VLT/X-shooter redshift
  41. GRB 240825A: SVOM/C-GFT optical observations
  42. GRB 240825A: Montarrenti Observatory optical observations
  43. GRB 240825A: Fermi-LAT detection
  44. GRB 240824B: KAIT optical upper limit
  45. GRB 240824B: Fermi GBM Observation
  46. Fermi GRB 240825A: Global MASTER-Net observations report
  47. GRB 240824B: NOT optical upper limit
  48. GRB 240825A: 1.6m Mephisto multi-band detection
  49. GRB 240825A: AKO Optical Afterglow Detection
  50. GRB 240825A: Nanshan/HMT optical afterglow observations
  51. GRB 240825A: Fermi GBM Final Real-time Localization
  52. GRB 240824B: Swift-XRT afterglow detection
  53. GRB 240824B: Swift/BAT arcminute localization of a burst
  54. Fermi GRB 240824C: Global MASTER-Net observations report
  55. GRB 240824C: Fermi GBM Final Localization
  56. GRB 240821A: Swift/UVOT observations of the XRT sources.
  57. GRB 240824B: MAXI/GSC detection
  58. GRB 240824B: Fermi GBM Final Real-time Localization
  59. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  60. GRB 240821A: Colibri Optical Upper Limit
  61. GRB 240821A: Swift-XRT observations
  62. GRB 240821A: REM optical/NIR upper limits
  63. GRB 240821A: LCO optical observations
  64. GRB 240821A: JinShan optical upper limits
  65. GRB 240821A: GMG Optical Upper Limit
  66. Fermi GRB 240821A: Global MASTER-Net observations report
  67. GRB 240821A: Fermi GBM Observation
  68. Fermi trigger No 745964969: Global MASTER-Net observations report
  69. Fermi trigger No 745925274: Global MASTER-Net observations report
  70. GRB 240821A: Swift ToO observations
  71. Fermi trigger No 746019401: Global MASTER-Net observations report
  72. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  73. Fermi trigger No 745935375: Global MASTER-Net observations report
  74. GRB240821A: EIRSAT-1 GMOD Detection
  75. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  76. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  77. Fermi GRB 240821B: Global MASTER-Net observations report
  78. GRB 240821A: SVOM/GRM observation
  79. GRB 240821A: SVOM/GRM observation
  80. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  81. GRB 240821B: Fermi GBM Final Localization
  82. Fermi trigger No 745866488: Global MASTER-Net observations report
  83. GRB 240821A: BALROG localization (Fermi Trigger 745958167 / GRB 240821775)
  84. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  85. GRB 240821A: Fermi GBM Final Real-time Localization
  86. Fermi trigger No 745873283: Global MASTER-Net observations report
  87. Fermi trigger No 745871958: Global MASTER-Net observations report
  88. Fermi Gamma-ray Burst Monitor trigger 745811685 / 240820080 is not a GRB
  89. GRB 240820A: Fermi GBM Final Real-time Localization
  90. GRB 240814A: SVOM/GRM observation
  91. GRB 240814C: SVOM/GRM observation
  92. GRB 240817A: Fermi GBM Final Real-time Localization
  93. GRB 240814B: GRBAlpha detection
  94. Fermi trigger No 745501396: Global MASTER-Net observations report
  95. Fermi GRB 240814A: Global MASTER-Net observations report
  96. Fermi GRB 240814C: Global MASTER-Net observations report
  97. Fermi trigger No 745306088: Global MASTER-Net observations report
  98. GRB 240814C: Fermi GBM Final Real-time Localization
  99. Fermi GRB 240814B: Global MASTER-Net observations report
  100. GRB 240814B: Fermi GBM Final Real-time Localization

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