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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"

36197 results found.

  1. GRB 240821A: Swift ToO observations
  2. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  3. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  4. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  5. Fermi GRB 240821B: Global MASTER-Net observations report
  6. EP240801a: Keck/LRIS spectroscopic redshift confirmation
  7. GRB 240821A: SVOM/GRM observation
  8. GRB 240821A: SVOM/GRM observation
  9. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  10. GRB 240821B: Fermi GBM Final Localization
  11. GRB 240821A: BALROG localization (Fermi Trigger 745958167 / GRB 240821775)
  12. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  13. GRB 240821A: Fermi GBM Final Real-time Localization
  14. GRB 240819A: Swift-XRT observations
  15. GRB 240819A: JinShan optical upper limits on one Swift/XRT source
  16. GRB 240820B: SVOM/GRM observation
  17. GRB 240819A: KAIT optical upper limit
  18. GRB 240819A : an X-ray transient detected by SVOM/ECLAIRs
  19. GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
  20. GRB 240819A: X-ray follow-up observation with EP-FXT
  21. Fermi Gamma-ray Burst Monitor trigger 745811685 / 240820080 is not a GRB
  22. GRB 240820A: Fermi GBM Final Real-time Localization
  23. GRB 240819A: Swift ToO observations
  24. GRB 240814A: SVOM/GRM observation
  25. GRB 240814C: SVOM/GRM observation
  26. GRB 240815A: SVOM/GRM observation
  27. GRB 240817A: Fermi GBM Final Real-time Localization
  28. GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  29. IBAS Alert n.10856: not a GRB
  30. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  31. EP240816b: KAIT optical upper limit
  32. GRB 240814B: GRBAlpha detection
  33. Fermi GRB 240814A: Global MASTER-Net observations report
  34. Fermi GRB 240814C: Global MASTER-Net observations report
  35. GRB 240814C: Fermi GBM Final Real-time Localization
  36. Fermi GRB 240814B: Global MASTER-Net observations report
  37. GRB 240812B: SVOM/GRM observation
  38. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  39. GRB 240814B: Fermi GBM Final Real-time Localization
  40. GRB 240814A: Fermi GBM Final Real-time Localization
  41. Konus-Wind detection of GRB 240811A
  42. Konus-Wind detection of GRB 240810A
  43. Fermi Gamma-ray Burst Monitor trigger 745220784/240813240 is not a GRB
  44. GRB 240809A: Correction to the VLA source position in GCN 37158
  45. GRB 240810A: SVOM/GRM observation
  46. Fermi Gamma-ray Burst Monitor trigger 240812940/745194848 is not a GRB
  47. Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
  48. Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
  49. GRB 240809A: ATA radio non-detection
  50. GRB 240812D: Fermi GBM Final Real-time Localization
  51. GRB 240812C: Fermi GBM Final Real-time Localization
  52. GRB 240809A : RAPAS follow-up observations
  53. GRB 240809A: VLA detection
  54. GRB 240809A: ALMA detection
  55. IPN triangulation of GRB 240810A (short)
  56. GRB 240811A: Swift-BAT refined analysis
  57. GRB 240809A: Swift-BAT refined analysis
  58. GRB 240812B: AstroSat CZTI detection of a long burst
  59. GRB 240811A: Bassano Bresciano Observatory upper limit
  60. GRB 240811A: Swift-XRT refined Analysis
  61. Fermi Gamma-ray Burst Monitor trigger 745135620/240812255 is not a GRB
  62. GRB 240811A: Swift/UVOT Upper Limits
  63. EP240801a: Assy-Turgen optical observations
  64. Fermi GRB 240810A: Global MASTER-Net observations report
  65. Fermi Gamma-ray Burst Monitor trigger 240812094/745121685 is not a GRB
  66. GRB 240812A: Fermi GBM Final Real-time Localization
  67. GRB 240811A: LCOGT Optical Upper Limit
  68. GRB 240811A: Enhanced Swift-XRT position
  69. GRB 240811A: Upper limits with Mephisto
  70. Konus-Wind detection of GRB 240809A
  71. Swift GRB 240811A: Global MASTER-Net observations report
  72. GRB 240811A: Swift detection of a burst
  73. Fermi Gamma-ray Burst Monitor trigger 745050426/240811269 is not a GRB
  74. GRB 240810A: Fermi GBM Final Real-time Localization
  75. GRB 240809A: REM detection of the optical afterglow
  76. GRB 240809A: Bassano Bresciano Observatory optical observations
  77. Konus-Wind detection of GRB 240807A (a counterpart of EP240807a)
  78. GRB 240809A: Conclusive redshift from VLT
  79. GRB 240809A: KAIT optical observations
  80. GRB 240808A: AstroSat CZTI detection
  81. GRB 240809A: GIT afterglow observations
  82. GRB 240809B: MAXI/GSC detection
  83. GRB 240809A: Swift/UVOT Detection
  84. GRB 240809A: Tentative redshift from NOT
  85. GRB 240809A: Swift-XRT refined Analysis
  86. IPN triangulation of GRB 240807A / EP 240807a
  87. Swift GRB 240809A: Global MASTER-Net observations report
  88. GRB 240809A: JinShan optical observations
  89. GRB 240809A: Enhanced Swift-XRT position
  90. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  91. GRB 240809A: SVOM/GRM observation
  92. GRB 240808A: SVOM/GRM observation
  93. GRB 240807A: SVOM/GRM observation
  94. GRB 240809A: Swift detection of a burst with a bright optical counterpart
  95. EP-WXT trigger 01709018832: SVOM/C-GFT observations of the star flare
  96. GRB 240807B: AstroSat CZTI detection of a short burst
  97. GRB 240801A: GRBAlpha detection
  98. GRB 240807B: Fermi GBM Final Localization
  99. GRB 240710B: VZLUSAT-2 detection
  100. GRB 240805A: ATCA Radio Upper Limits

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