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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"

28221 results found.

  1. GRB 240829B: Fermi GBM Final Localization
  2. GRB 240828A: Fermi GBM Observation
  3. GRB 240828A: KAIT Optical Afterglow Candidate
  4. GRB 240825A: SVOM/VT optical detection
  5. GRB 240828A: Swift-XRT afterglow detection
  6. GRB 240825A: iTelescope optical observations
  7. GRB 240828B: Swift-XRT afterglow detection
  8. GRB 240829A: Swift detection of a burst
  9. GRB 240828A: Fermi-LAT detection
  10. GRB 240828A: Tiled Swift observations
  11. GRB 240828A: AstroSat CZTI detection of a long burst
  12. GRB 240819A as a likely X-Ray Flash
  13. GRB 240828B: Swift ToO observations
  14. GRB 240825A: VLA detection
  15. SVOM GRB 240821A: optical afterglow discovery
  16. GRB 240828B : Detection of a possible very soft X-ray transient by SVOM/ECLAIRs
  17. GRB 240828A: Fermi GBM Final Real-time Localization
  18. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  19. GRB 240825A: GECAM detection
  20. GRB 240825A: ALMA detection
  21. GRB 240825A: SAO RAS optical observations
  22. GRB 240824A: GIT optical upper limit
  23. GRB 240819A: Swift afterglow confirmation
  24. GRB 240825A: TNG optical photometry and spectroscopy
  25. GRB 240824B: Ondrejov D50 optical limit
  26. GRB 240825A: KAIT optical observations
  27. GRB 240825A: PRIME near-infrared detection
  28. Konus-Wind detection of GRB 240825A (bright/long)
  29. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  30. GRB 240825A: AKO Optical Follow-Up Observations
  31. GRB 240825A: AstroSat CZTI detection of the long bright burst
  32. GRB 240825A: Swift/UVOT Detection
  33. GRB 240825A: REM detection of the optical/NIR afterglow
  34. GRB 240825A: Swift-XRT refined Analysis
  35. GRB 240825A: VLT/X-shooter redshift
  36. GRB 240825A: SVOM/C-GFT optical observations
  37. GRB 240825A: Enhanced Swift-XRT position
  38. GRB 240825A: Fermi-LAT detection
  39. GRB 240825A: LCO optical observations
  40. GRB 240824B: KAIT optical upper limit
  41. GRB 240824B: Fermi GBM Observation
  42. GRB 240824B: NOT optical upper limit
  43. GRB 240825A: 1.6m Mephisto multi-band detection
  44. GRB 240825A: AKO Optical Afterglow Detection
  45. GRB 240825A: Skynet Optical Afterglow observations
  46. GRB 240825A: Nanshan/HMT optical afterglow observations
  47. GRB 240825A: Swift detection of a burst with a bright optical counterpart
  48. GRB 240825A: Fermi GBM Final Real-time Localization
  49. GRB 240824A: SVOM/C-GFT optical upper limit
  50. GRB 240824B: Swift-XRT afterglow detection
  51. GRB 240824A: Swift-XRT observations
  52. GRB 240824B: Swift/BAT arcminute localization of a burst
  53. GRB 240824B: Swift ToO observations
  54. GRB 240824C: Fermi GBM Final Localization
  55. GRB 240824A: Swift/UVOT Upper Limits
  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. GRB 240824A: Retraction of GCN 37255
  60. GRB240824A: GRANDMA/TAROT-TCA Upper Limit
  61. GRB 240824A: KAIT optical upper limit
  62. GRB 240824A: Skynet Optical Afterglow Discovery
  63. GRB 240824A: Swift detection of a burst
  64. GRB 240821A: Colibri Optical Upper Limit
  65. EP240820a: PRIME J-band Observations
  66. GRB 240821A: Swift-XRT observations
  67. GRB 240822A: AstroSat CZTI detection of a short burst
  68. GRB 240821A: REM optical/NIR upper limits
  69. GRB 240821A: JinShan optical upper limits
  70. GRB 240821A: SVOM/VT follow-up and optical upper limit
  71. GRB 240821A: GMG Optical Upper Limit
  72. GRB 240821A: Swift ToO observations
  73. GRB240821A: EIRSAT-1 GMOD Detection
  74. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  75. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  76. EP240801a: Keck/LRIS spectroscopic redshift confirmation
  77. GRB 240821B: Fermi GBM Final Localization
  78. Trigger 1249878: Swift detection of another burst from SGR 1E 1841-045 / Kes 73
  79. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  80. GRB 240821A: Fermi GBM Final Real-time Localization
  81. GRB 240819A: Swift-XRT observations
  82. GRB 240819A: JinShan optical upper limits on one Swift/XRT source
  83. EP240820a: EP detection of a fast X-ray transient
  84. GRB 240819A: KAIT optical upper limit
  85. EP240816a: PRIME upper limits
  86. Trigger 1249653: Swift detection of SGR 1E 1841-045 / Kes 73
  87. GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
  88. GRB 240820A: Fermi GBM Final Real-time Localization
  89. GRB 240819A: Swift ToO observations
  90. EP240816a: BOOTES-6/DPRT optical upper limit
  91. GRB 240817A: Fermi GBM Final Real-time Localization
  92. GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  93. GRB 240814B: GRBAlpha detection
  94. EP240816a: EP detection of a fast X-ray transient and follow-up observation
  95. EP240816b: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  96. GRB 240814C: Fermi GBM Final Real-time Localization
  97. GRB 240812B: SVOM/GRM observation
  98. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  99. GRB 240814B: Fermi GBM Final Real-time Localization
  100. GRB 240814A: Fermi GBM Final Real-time Localization

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