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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"

36400 results found.

  1. GRB 240821A: SVOM/VT follow-up and optical upper limit
  2. GRB 240821A: GMG Optical Upper Limit
  3. Fermi GRB 240821A: Global MASTER-Net observations report
  4. GRB 240821A: Fermi GBM Observation
  5. GRB 240821A: Swift ToO observations
  6. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  7. GRB240821A: EIRSAT-1 GMOD Detection
  8. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  9. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  10. Fermi GRB 240821B: Global MASTER-Net observations report
  11. EP240801a: Keck/LRIS spectroscopic redshift confirmation
  12. GRB 240821A: SVOM/GRM observation
  13. GRB 240821A: SVOM/GRM observation
  14. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  15. GRB 240821B: Fermi GBM Final Localization
  16. GRB 240821A: BALROG localization (Fermi Trigger 745958167 / GRB 240821775)
  17. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  18. GRB 240821A: Fermi GBM Final Real-time Localization
  19. GRB 240819A: Swift-XRT observations
  20. GRB 240819A: JinShan optical upper limits on one Swift/XRT source
  21. GRB 240820B: SVOM/GRM observation
  22. GRB 240819A: KAIT optical upper limit
  23. GRB 240819A : an X-ray transient detected by SVOM/ECLAIRs
  24. GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
  25. GRB 240819A: X-ray follow-up observation with EP-FXT
  26. Fermi Gamma-ray Burst Monitor trigger 745811685 / 240820080 is not a GRB
  27. GRB 240820A: Fermi GBM Final Real-time Localization
  28. GRB 240819A: Swift ToO observations
  29. GRB 240814A: SVOM/GRM observation
  30. GRB 240814C: SVOM/GRM observation
  31. GRB 240815A: SVOM/GRM observation
  32. GRB 240817A: Fermi GBM Final Real-time Localization
  33. GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  34. IBAS Alert n.10856: not a GRB
  35. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  36. EP240816b: KAIT optical upper limit
  37. GRB 240814B: GRBAlpha detection
  38. Fermi GRB 240814A: Global MASTER-Net observations report
  39. Fermi GRB 240814C: Global MASTER-Net observations report
  40. GRB 240814C: Fermi GBM Final Real-time Localization
  41. Fermi GRB 240814B: Global MASTER-Net observations report
  42. GRB 240812B: SVOM/GRM observation
  43. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  44. GRB 240814B: Fermi GBM Final Real-time Localization
  45. GRB 240814A: Fermi GBM Final Real-time Localization
  46. Konus-Wind detection of GRB 240811A
  47. Konus-Wind detection of GRB 240810A
  48. Fermi Gamma-ray Burst Monitor trigger 745220784/240813240 is not a GRB
  49. GRB 240809A: Correction to the VLA source position in GCN 37158
  50. GRB 240810A: SVOM/GRM observation
  51. Fermi Gamma-ray Burst Monitor trigger 240812940/745194848 is not a GRB
  52. Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
  53. Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
  54. GRB 240809A: ATA radio non-detection
  55. GRB 240812D: Fermi GBM Final Real-time Localization
  56. GRB 240812C: Fermi GBM Final Real-time Localization
  57. GRB 240809A : RAPAS follow-up observations
  58. GRB 240809A: VLA detection
  59. GRB 240809A: ALMA detection
  60. IPN triangulation of GRB 240810A (short)
  61. GRB 240811A: Swift-BAT refined analysis
  62. GRB 240809A: Swift-BAT refined analysis
  63. GRB 240812B: AstroSat CZTI detection of a long burst
  64. IceCube-240808A: Upper limits from a search for additional neutrino events in IceCube
  65. GRB 240811A: Bassano Bresciano Observatory upper limit
  66. GRB 240811A: Swift-XRT refined Analysis
  67. Fermi Gamma-ray Burst Monitor trigger 745135620/240812255 is not a GRB
  68. GRB 240811A: Swift/UVOT Upper Limits
  69. EP240801a: Assy-Turgen optical observations
  70. Fermi GRB 240810A: Global MASTER-Net observations report
  71. Fermi Gamma-ray Burst Monitor trigger 240812094/745121685 is not a GRB
  72. GRB 240812A: Fermi GBM Final Real-time Localization
  73. GRB 240811A: LCOGT Optical Upper Limit
  74. GRB 240811A: Enhanced Swift-XRT position
  75. GRB 240811A: Upper limits with Mephisto
  76. Konus-Wind detection of GRB 240809A
  77. Swift GRB 240811A: Global MASTER-Net observations report
  78. GRB 240811A: Swift detection of a burst
  79. Fermi Gamma-ray Burst Monitor trigger 745050426/240811269 is not a GRB
  80. GRB 240810A: Fermi GBM Final Real-time Localization
  81. GRB 240809A: REM detection of the optical afterglow
  82. GRB 240809A: Bassano Bresciano Observatory optical observations
  83. Konus-Wind detection of GRB 240807A (a counterpart of EP240807a)
  84. GRB 240809A: Conclusive redshift from VLT
  85. GRB 240809A: KAIT optical observations
  86. GRB 240808A: AstroSat CZTI detection
  87. GRB 240809A: GIT afterglow observations
  88. GRB 240809B: MAXI/GSC detection
  89. GRB 240809A: Swift/UVOT Detection
  90. GRB 240809A: Tentative redshift from NOT
  91. GRB 240809A: Swift-XRT refined Analysis
  92. IPN triangulation of GRB 240807A / EP 240807a
  93. Swift GRB 240809A: Global MASTER-Net observations report
  94. GRB 240809A: JinShan optical observations
  95. GRB 240809A: Enhanced Swift-XRT position
  96. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  97. GRB 240809A: SVOM/GRM observation
  98. GRB 240808A: SVOM/GRM observation
  99. GRB 240807A: SVOM/GRM observation
  100. GRB 240809A: Swift detection of a burst with a bright optical counterpart

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