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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"

39257 results found.

  1. EP251130a: JinShan near-infrared observations
  2. Fermi Gamma-ray Burst Monitor trigger 786496343/251203967 is not a GRB
  3. GRB 251203C: LCO optical afterglow confirmation
  4. GRB 251203C: SVOM/VT optical counterpart
  5. GRB 251203C: EP-FXT follow-up observation
  6. GRB 251129A/EP251129a : SVOM/ECLAIRs refined analysis
  7. GRB 251129B: GECAM-B observation of a burst
  8. GRB 251203B: Swift-XRT observations
  9. GRB 251203B: confirmation of a stellar flare by BOOTES-2
  10. GRB 251203B : SVOM trigger sb25120304 is not a GRB
  11. GRB 251203C: LCO optical upper limits
  12. GRB 251203B: LCO optical upper limits
  13. GRB 251203B: SVOM/VT optical observation
  14. GRB 251202A / EP251202a: Liverpool Telescope optical follow-up observations
  15. GRB 251203C: SVOM detection of a burst
  16. SVOM GRB251203.77: Global MASTER-Net observations report
  17. SVOM GRB251203B: Global MASTER-Net observations report
  18. GRB 251203B: SVOM detection of a burst
  19. GRB 251129A / EP251129a: SVOM/VT optical color bluer
  20. GRB 251201B: Insight-HXMT/HE detection
  21. EP251202a / GRB 251202A: Insight-HXMT/HE detection
  22. GRB 251203A: Fermi GBM Final Real-time Localization
  23. EP251202a / GRB251202A: AstroSat CZTI detection
  24. GRB 251202A / EP251202a: SVOM/VT optical observation
  25. GRB 251201B: Fermi GBM Observation
  26. EP251202a/GRB 251202A: KAIT optical observations
  27. EP251130a: ULL-ASTRO-MASTER late detection of the optical afterglow with LCO 1-m telescope at Teide Observatory
  28. Fermi GRB 251202B: Global MASTER-Net observations report
  29. GRB 251202B: Fermi GBM Final Real-time Localization
  30. IPN triangulation of GRB 251129B (short/hard)
  31. GRB251129A/EP251129a: Swift UVOT detection
  32. GRB 251129B: AstroSat CZTI detection
  33. GRB 251202A: Fermi GBM Observation
  34. GRB 251202A: Swift/UVOT Detection
  35. GRB 251201B: Kilonova-Catcher optical afterglow detection
  36. GRB 251201B: Swift/UVOT Detection
  37. GRB 251130B: Glowbug gamma-ray detection
  38. GRB 251201B: GECAM-B observation of a long burst
  39. GRB 251122A/EP251122a: CrAO ZTSh optical observations
  40. EP251202a / GRB 251202A: LCO r- and i-band optical detection
  41. GRB 251202A: GOTO optical afterglow detection
  42. EP251202a/GRB 251202A: refined analysis of the EP-WXT observations
  43. GRB 251201A: GECAM-B observation of a burst
  44. GRB 251126A: SAO RAS optical marginal detection
  45. GRB 251202A: Swift-XRT afterglow detection
  46. EP251129a/GRB 251129A: NOWT Detection
  47. GRB 251126A: SVOM/VT optical observation
  48. EP251202a / GRB 251202A: NOT spectroscopic redshift z = 2.785
  49. Fermi GRB 251202A: Global MASTER-Net observations report
  50. EP251202a/GRB 251202A: Einstein Probe detection of an X-ray transient
  51. GRB 251201B: Swift-XRT refined Analysis
  52. GRB 251202A: Fermi GBM Final Real-time Localization
  53. GRB 251201A: SVOM/GRM observation of a burst
  54. GRB 251201B: SVOM/VT optical fading
  55. Swift GRB 251201B : MASTER optical counterpart detection
  56. GRB 251201B: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at Sutherland Observatory
  57. Swift GRB 251201B: Global MASTER-Net observations report
  58. GRB 251201B: Enhanced Swift-XRT position
  59. EP251118a: Mondy, CrAO, Assy and SAO RAS/Zeiss-1000 optical observations
  60. GRB 251130B: AstroSat CZTI detection
  61. GRB 251201B: Swift detection of a burst with an optical counterpart
  62. GRB 251201B: Fermi GBM Final Real-time Localization
  63. EP251130a: Mondy optical observations
  64. SVOM GRB251201.19: Global MASTER-Net observations report
  65. EP251130a: SAO RAS optical observations
  66. EP251130a: KAIT optical observations
  67. EP251130A: Optical observation from 1.3m DFOT
  68. EP251130a: JinShan optical observations
  69. GRB 251201A: MAXI/GSC detection
  70. Fermi GRB 251130B: Global MASTER-Net observations report
  71. GRB 251127A: SVOM/GRM observation
  72. IceCube Alert 251130.75: Global MASTER-Net observations report
  73. IceCube-251130A - IceCube observation of a high-energy neutrino candidate track-like event
  74. GRB 251130B: Fermi GBM Final Localization Correction
  75. EP251130a: Global MASTER-Net observations report
  76. GRB 251130B: Fermi GBM Final Real-time Localization
  77. EP251130a: COLIBRÍ optical counterpart candidate
  78. EP251129a/GRB 251129A: EP-FXT follow-up observations
  79. GRB 251130A: Fermi GBM Final Real-time Localization
  80. GRB 251129A / EP251129a: GTC/OSIRIS+ spectroscopic redshift z = 1.460
  81. GRB 251129A / EP251129a: OSN and CAHA optical follow-up
  82. GRB 251128A: AstroSat CZTI detection
  83. GRB 251129A / EP251129a: SAO RAS optical observations
  84. GRB 251126A: SAO RAS optical observations
  85. GRB 251128A: GECAM-B detection
  86. GRB 251128A: SVOM/GRM observation of a long burst
  87. GRB 251128A: Insight-HXMT/HE detection
  88. SVOM GRB 251129A : MASTER optical counterpart detection
  89. GRB 251129A: Swift-XRT afterglow detection
  90. GRB 251129A: Swift ToO observations
  91. GRB 251129A / EP251129a: SVOM/VT optical fading
  92. EP251129a: Global MASTER-Net observations report
  93. GRB 251129A: Optical Observations via Virtual Telescope Project, Italy
  94. EP251129a/GRB 251129A : Einstein Probe detection of an X-ray transient
  95. GRB 251129A: Correction to the position of the optical counterpar
  96. GRB 251129A: SVOM/VT optical counterpart confirmation with VHF data
  97. GRB 251128A: Fermi GBM Observation
  98. GRB 251129A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  99. GRB 251129A: SVOM detection of a burst
  100. SVOM GRB251129A: Global MASTER-Net observations report

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