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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"

36414 results found.

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

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