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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"

11610 results found.

  1. GRB 251208B: Swift-XRT afterglow detection
  2. GRB 251209A: Fermi GBM Final Real-time Localization
  3. GRB 251208B: Fermi GBM Observation
  4. GRB 251208B: GROWTH-India Telescope optical upper limits
  5. GRB 251208A: SVOM/GRM observation of a short burst
  6. GRB 251208C: SVOM/GRM observation of a short burst
  7. GRB 251208B: Swift ToO observations
  8. GRB 251208B: Fermi-LAT detection
  9. GRB 251208B: Swift/BAT-GUANO arcminute localization of a burst
  10. GRB 251208C: Fermi GBM Final Real-time Localization
  11. GRB 251208B: Fermi GBM Final Real-time Localization
  12. GRB 251208A: Fermi GBM Final Real-time Localization
  13. Konus-Wind detection of GRB 251118A
  14. GRB 251126B: Fermi GBM Final Localization
  15. GRB 251203A: Insight-HXMT/HE detection
  16. GRB 251202A / EP251202a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm and 1-m telescopes at McDonald Observatory
  17. GRB 251202A: SVOM/GRM observation
  18. GRB 251203A: GECAM-B observation of a burst
  19. GRB 251203A: SVOM/GRM observation
  20. GRB 251201B: SALT spectroscopic redshift z = 1.599
  21. GRB 251203A: AstroSat CZTI detection
  22. Fermi Gamma-ray Burst Monitor trigger 786496343/251203967 is not a GRB
  23. GRB 251202A / EP251202a: Liverpool Telescope optical follow-up observations
  24. GRB 251201B: Insight-HXMT/HE detection
  25. EP251202a / GRB 251202A: Insight-HXMT/HE detection
  26. GRB 251203A: Fermi GBM Final Real-time Localization
  27. EP251202a / GRB251202A: AstroSat CZTI detection
  28. GRB 251202A / EP251202a: SVOM/VT optical observation
  29. GRB 251201B: Fermi GBM Observation
  30. EP251202a/GRB 251202A: KAIT optical observations
  31. Fermi GRB 251202B: Global MASTER-Net observations report
  32. GRB 251202B: Fermi GBM Final Real-time Localization
  33. GRB 251202A: Fermi GBM Observation
  34. GRB 251201B: Kilonova-Catcher optical afterglow detection
  35. GRB 251130B: Glowbug gamma-ray detection
  36. GRB 251201B: GECAM-B observation of a long burst
  37. Fermi-LAT Gamma-ray Observations of IceCube-251130A
  38. EP251202a / GRB 251202A: LCO r- and i-band optical detection
  39. GRB 251202A: GOTO optical afterglow detection
  40. EP251202a / GRB 251202A: NOT spectroscopic redshift z = 2.785
  41. Fermi GRB 251202A: Global MASTER-Net observations report
  42. EP251202a/GRB 251202A: Einstein Probe detection of an X-ray transient
  43. GRB 251202A: Fermi GBM Final Real-time Localization
  44. GRB 251201B: SVOM/VT optical fading
  45. Swift GRB 251201B : MASTER optical counterpart detection
  46. GRB 251201B: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at Sutherland Observatory
  47. GRB 251130B: AstroSat CZTI detection
  48. GRB 251201B: Fermi GBM Final Real-time Localization
  49. Fermi GRB 251130B: Global MASTER-Net observations report
  50. GRB 251127A: SVOM/GRM observation
  51. IceCube-251130A - IceCube observation of a high-energy neutrino candidate track-like event
  52. GRB 251130B: Fermi GBM Final Localization Correction
  53. GRB 251130B: Fermi GBM Final Real-time Localization
  54. GRB 251130A: Fermi GBM Final Real-time Localization
  55. GRB 251128A: AstroSat CZTI detection
  56. GRB 251128A: GECAM-B detection
  57. GRB 251128A: SVOM/GRM observation of a long burst
  58. GRB 251128A: Insight-HXMT/HE detection
  59. GRB 251128A: Fermi GBM Observation
  60. GRB 251128A: Swift/BAT-GUANO localization skymap of a burst
  61. Fermi GRB 251128A: Global MASTER-Net observations report
  62. GRB 251127A: Glowbug gamma-ray detection
  63. GRB 251128A: Fermi GBM Final Real-time Localization
  64. GRB 251125B: GECAM-B detection
  65. Fermi GRB 251127A: Global MASTER-Net observations report
  66. GRB 251127A: Fermi GBM Final Real-time Localization
  67. GRB 251121A: Fermi GBM Observation
  68. GRB 251125B: COLIBRÍ further observations and photometric redshift upper limit of z < 3
  69. GRB 251125B: COLIBRÍ observations of fading of the MASTER OT candidate
  70. Fermi GRB 251125B : MASTER OT J155558.56+581224.1 optical counterpart discovery
  71. Fermi GRB 251125B: Global MASTER-Net observations report
  72. GRB 251125B: Fermi GBM Final Real-time Localization
  73. Fermi GRB 251125A: Global MASTER-Net observations report
  74. GRB 251125A: Fermi GBM Final Real-time Localization
  75. GRB 251124A: Fermi GBM Localization by automated pipeline
  76. GRB 251122B: Fermi GBM Final Localization
  77. Fermi GRB 251124a: Global MASTER-Net observations report
  78. GRB 251124a: Fermi GBM Final Localization
  79. GRB 251121A: Swift/BAT-GUANO localization skymap of a short burst
  80. GRB 251121A: Glowbug gamma-ray detection of a likely short burst
  81. GRB 251115A: Fermi GBM Observation
  82. GRB 251121A: Fermi GBM Final Real-time Localization
  83. Fermi Gamma-ray Burst Monitor trigger 785388351 / 251121143 is not a GRB
  84. Fermi trigger No 785388351: Global MASTER-Net observations report
  85. GRB 251118A: Swift/UVOT Detection
  86. GRB 251118A: Glowbug gamma-ray detection
  87. GRB 251118A: Fermi GBM Observation
  88. GRB 251118A: Swift-XRT afterglow detection
  89. GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
  90. GRB 251118A: GECAM-B detection
  91. GRB 251118A: NuSTAR detection of bright prompt emission
  92. GRB 251117A: Swift-XRT observations
  93. GRB 251117A: Insight-HXMT/HE detection
  94. GRB 251118A: Fermi-LAT detection
  95. GRB 251118A: Swift ToO observations
  96. Fermi GRB 251118B: Global MASTER-Net observations report
  97. GRB 251118B: Fermi GBM Final Real-time Localization
  98. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  99. GRB 251118A: BALROG localization (Fermi Trigger 785190695 / GRB 251118855)
  100. GRB 251117A: FTW Observations of Swift candidate X-ray sources

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