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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"

36315 results found.

  1. GRB 240824B: Fermi GBM Final Real-time Localization
  2. GRB 240824A: Retraction of GCN 37255
  3. GRB240824A: GRANDMA/TAROT-TCA Upper Limit
  4. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  5. GRB 240824A: KAIT optical upper limit
  6. GRB 240824A: Skynet Optical Afterglow Discovery
  7. GRB 240824A: Swift detection of a burst
  8. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  9. GRB 240821A: Colibri Optical Upper Limit
  10. GRB 240821A: Swift-XRT observations
  11. GRB 240822A: AstroSat CZTI detection of a short burst
  12. GRB 240821A: REM optical/NIR upper limits
  13. GRB 240821A: LCO optical observations
  14. GRB 240821A: JinShan optical upper limits
  15. GRB 240809A: Mondy and AbAO Optical Observations
  16. GRB 240821A: SVOM/VT follow-up and optical upper limit
  17. GRB 240821A: GMG Optical Upper Limit
  18. Fermi GRB 240821A: Global MASTER-Net observations report
  19. GRB 240821A: Fermi GBM Observation
  20. GRB 240821A: Swift ToO observations
  21. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  22. GRB240821A: EIRSAT-1 GMOD Detection
  23. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  24. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  25. Fermi GRB 240821B: Global MASTER-Net observations report
  26. EP240801a: Keck/LRIS spectroscopic redshift confirmation
  27. GRB 240821A: SVOM/GRM observation
  28. GRB 240821A: SVOM/GRM observation
  29. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  30. GRB 240821B: Fermi GBM Final Localization
  31. GRB 240821A: BALROG localization (Fermi Trigger 745958167 / GRB 240821775)
  32. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  33. GRB 240821A: Fermi GBM Final Real-time Localization
  34. GRB 240819A: Swift-XRT observations
  35. GRB 240819A: JinShan optical upper limits on one Swift/XRT source
  36. GRB 240820B: SVOM/GRM observation
  37. GRB 240819A: KAIT optical upper limit
  38. GRB 240819A : an X-ray transient detected by SVOM/ECLAIRs
  39. GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
  40. GRB 240819A: X-ray follow-up observation with EP-FXT
  41. Fermi Gamma-ray Burst Monitor trigger 745811685 / 240820080 is not a GRB
  42. GRB 240820A: Fermi GBM Final Real-time Localization
  43. GRB 240819A: Swift ToO observations
  44. GRB 240814A: SVOM/GRM observation
  45. GRB 240814C: SVOM/GRM observation
  46. GRB 240815A: SVOM/GRM observation
  47. GRB 240817A: Fermi GBM Final Real-time Localization
  48. GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  49. IBAS Alert n.10856: not a GRB
  50. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  51. EP240816b: KAIT optical upper limit
  52. GRB 240814B: GRBAlpha detection
  53. Fermi GRB 240814A: Global MASTER-Net observations report
  54. Fermi GRB 240814C: Global MASTER-Net observations report
  55. GRB 240814C: Fermi GBM Final Real-time Localization
  56. Fermi GRB 240814B: Global MASTER-Net observations report
  57. GRB 240812B: SVOM/GRM observation
  58. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  59. GRB 240814B: Fermi GBM Final Real-time Localization
  60. GRB 240814A: Fermi GBM Final Real-time Localization
  61. Konus-Wind detection of GRB 240811A
  62. Konus-Wind detection of GRB 240810A
  63. Fermi Gamma-ray Burst Monitor trigger 745220784/240813240 is not a GRB
  64. GRB 240809A: Correction to the VLA source position in GCN 37158
  65. GRB 240810A: SVOM/GRM observation
  66. Fermi Gamma-ray Burst Monitor trigger 240812940/745194848 is not a GRB
  67. Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
  68. Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
  69. GRB 240809A: ATA radio non-detection
  70. GRB 240812D: Fermi GBM Final Real-time Localization
  71. GRB 240812C: Fermi GBM Final Real-time Localization
  72. GRB 240809A : RAPAS follow-up observations
  73. GRB 240809A: VLA detection
  74. GRB 240809A: ALMA detection
  75. IPN triangulation of GRB 240810A (short)
  76. GRB 240811A: Swift-BAT refined analysis
  77. GRB 240809A: Swift-BAT refined analysis
  78. GRB 240812B: AstroSat CZTI detection of a long burst
  79. IceCube-240808A: Upper limits from a search for additional neutrino events in IceCube
  80. GRB 240811A: Bassano Bresciano Observatory upper limit
  81. GRB 240811A: Swift-XRT refined Analysis
  82. Fermi Gamma-ray Burst Monitor trigger 745135620/240812255 is not a GRB
  83. GRB 240811A: Swift/UVOT Upper Limits
  84. EP240801a: Assy-Turgen optical observations
  85. Fermi GRB 240810A: Global MASTER-Net observations report
  86. Fermi Gamma-ray Burst Monitor trigger 240812094/745121685 is not a GRB
  87. GRB 240812A: Fermi GBM Final Real-time Localization
  88. GRB 240811A: LCOGT Optical Upper Limit
  89. GRB 240811A: Enhanced Swift-XRT position
  90. GRB 240811A: Upper limits with Mephisto
  91. Konus-Wind detection of GRB 240809A
  92. Swift GRB 240811A: Global MASTER-Net observations report
  93. GRB 240811A: Swift detection of a burst
  94. Fermi Gamma-ray Burst Monitor trigger 745050426/240811269 is not a GRB
  95. GRB 240810A: Fermi GBM Final Real-time Localization
  96. GRB 240809A: REM detection of the optical afterglow
  97. GRB 240809A: Bassano Bresciano Observatory optical observations
  98. Konus-Wind detection of GRB 240807A (a counterpart of EP240807a)
  99. GRB 240809A: Conclusive redshift from VLT
  100. GRB 240809A: KAIT optical observations

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