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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"

28216 results found.

  1. Konus-Wind detection of GRB 251118A
  2. GRB 251205A: Zeiss-1000 Koshka observatory optical observations
  3. GRB 251205A: GOTO optical afterglow detection
  4. GRB 251205A: NOT optical observations
  5. GRB 251205A: GTC/OSIRIS+ redshift z = 1.100
  6. GRB 251205A: Enhanced Swift-XRT position
  7. Swift GRB 251205A : MASTER OT detection with host galaxy
  8. GRB 251205A: Swift detection of a burst with an optical afterglow
  9. GRB 251126B: Fermi GBM Final Localization
  10. GRB 251203A: Insight-HXMT/HE detection
  11. SVOM/sb25120502: SVOM detection of a faint X-ray transient candidate
  12. GRB 251202A / EP251202a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm and 1-m telescopes at McDonald Observatory
  13. GRB 251202A: SVOM/GRM observation
  14. GRB 251201B: SALT spectroscopic redshift z = 1.599
  15. GRB 251129B: Glowbug gamma-ray detection of a short burst
  16. GRB 251203A: AstroSat CZTI detection
  17. GRB 251203C: LCO optical afterglow confirmation
  18. GRB 251203C: SVOM/VT optical counterpart
  19. GRB 251129A/EP251129a : SVOM/ECLAIRs refined analysis
  20. GRB 251203B: Swift-XRT observations
  21. GRB 251203B: confirmation of a stellar flare by BOOTES-2
  22. GRB 251203B : SVOM trigger sb25120304 is not a GRB
  23. GRB 251203B: LCO optical upper limits
  24. GRB 251202A / EP251202a: Liverpool Telescope optical follow-up observations
  25. GRB 251203C: SVOM detection of a burst
  26. GRB 251203B: SVOM detection of a burst
  27. GRB 251129A / EP251129a: SVOM/VT optical color bluer
  28. GRB 251201B: Insight-HXMT/HE detection
  29. EP251202a / GRB 251202A: Insight-HXMT/HE detection
  30. EP251130a: MAO/AZT-22 optical observations
  31. GRB 251203A: Fermi GBM Final Real-time Localization
  32. EP251202a / GRB251202A: AstroSat CZTI detection
  33. GRB 251201B: Fermi GBM Observation
  34. EP251202a/GRB 251202A: KAIT optical observations
  35. EP251130a: ULL-ASTRO-MASTER late detection of the optical afterglow with LCO 1-m telescope at Teide Observatory
  36. GRB 251202B: Fermi GBM Final Real-time Localization
  37. IPN triangulation of GRB 251129B (short/hard)
  38. GRB251129A/EP251129a: Swift UVOT detection
  39. GRB 251129B: AstroSat CZTI detection
  40. GRB 251202A: Fermi GBM Observation
  41. GRB 251202A: Swift/UVOT Detection
  42. GRB 251201B: Kilonova-Catcher optical afterglow detection
  43. GRB 251201B: Swift/UVOT Detection
  44. GRB 251130B: Glowbug gamma-ray detection
  45. EP251202a / GRB 251202A: LCO r- and i-band optical detection
  46. GRB 251202A: GOTO optical afterglow detection
  47. GRB 251126A: SAO RAS optical marginal detection
  48. GRB 251202A: Swift-XRT afterglow detection
  49. EP251129a/GRB 251129A: NOWT Detection
  50. EP251130a: SVOM/VT optical observation
  51. EP251202a / GRB 251202A: NOT spectroscopic redshift z = 2.785
  52. EP251202a/GRB 251202A: Einstein Probe detection of an X-ray transient
  53. GRB 251201B: Swift-XRT refined Analysis
  54. GRB 251202A: Fermi GBM Final Real-time Localization
  55. GRB 251201B: SVOM/VT optical fading
  56. Swift GRB 251201B : MASTER optical counterpart detection
  57. GRB 251201B: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at Sutherland Observatory
  58. GRB 251201B: Enhanced Swift-XRT position
  59. GRB 251130B: AstroSat CZTI detection
  60. GRB 251201B: Swift detection of a burst with an optical counterpart
  61. GRB 251201B: Fermi GBM Final Real-time Localization
  62. EP251130a: Mondy optical observations
  63. EP251130a: Optical detections with Kinder observations
  64. EP251130a: SAO RAS optical observations
  65. EP251130a: KAIT optical observations
  66. EP251130A: Optical observation from 1.3m DFOT
  67. GRB 251201A: MAXI/GSC detection
  68. IceCube-251130A - IceCube observation of a high-energy neutrino candidate track-like event
  69. EP251130a: Swift-XRT counterpart detection
  70. GRB 251130B: Fermi GBM Final Localization Correction
  71. GRB 251130B: Fermi GBM Final Real-time Localization
  72. EP251130a: Einstein Probe detection of an X-ray transient
  73. GRB 251130A: Fermi GBM Final Real-time Localization
  74. GRB 251129A / EP251129a: GTC/OSIRIS+ spectroscopic redshift z = 1.460
  75. GRB 251129A / EP251129a: OSN and CAHA optical follow-up
  76. GRB 251128A: AstroSat CZTI detection
  77. GRB 251129A / EP251129a: SAO RAS optical observations
  78. GRB 251126A: SAO RAS optical observations
  79. GRB 251128A: GECAM-B detection
  80. GRB 251128A: Insight-HXMT/HE detection
  81. SVOM GRB 251129A : MASTER optical counterpart detection
  82. GRB 251129A: Swift-XRT afterglow detection
  83. GRB 251129A: Swift ToO observations
  84. EP251129a/GRB 251129A : Einstein Probe detection of an X-ray transient
  85. GRB 251129A: SVOM detection of a burst
  86. GRB 251129A: SVOM detection of a burst
  87. GRB 251126A: TShAO, Mondy, and AbAO optical observations
  88. GRB 251127A: Glowbug gamma-ray detection
  89. GRB 251126A: OHP/T193 optical observations and tentative spectroscopic redshift
  90. GRB 251126A: further SAO RAS optical observations
  91. GRB 250702B: detection of the compact radio counterpart 139 days after the burst
  92. GRB251126A: MAO/AZT-22 optical observations
  93. GRB 251128A: Fermi GBM Final Real-time Localization
  94. GRB251126A: Continued optical observation from 1.3m DFOT
  95. GRB 251126A: Swift/UVOT Detection
  96. EP251124a: Pan-STARRS ri-band imaging and photometry
  97. GRB 251126A: Mondy and SAO RAS optical observations
  98. GRB 251126A: Swift-XRT refined Analysis
  99. GRB 251126A : MITSuME Akeno optical afterglow candidate detection
  100. GRB 251126A: NOT optical observations

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