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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"

11621 results found.

  1. Konus-Wind detection of GRB 251028A
  2. GRB 251031A: BALROG localization (Fermi Trigger 783588065 / GRB 251031306)
  3. GRB 251031A: Fermi GBM Final Real-time Localization
  4. GRB 251025C: SVOM/GRM observation
  5. GRB 251028A: GECAM-B detection
  6. GRB 251028A: SVOM/GRM observation
  7. GRB 251028A: Fermi GBM Observation
  8. GRB 251022A: Swift-XRT confirmation of fading
  9. GRB 251026B: LBT near-infrared observations
  10. GRB 250926B: VZLUSAT-2 detection
  11. GRB 250926A: VZLUSAT-2 detection
  12. GRB 251026B: Fermi GBM Observation
  13. GRB 251028B: Fermi/GBM observation
  14. GRB 251028B: Swift/BAT-GUANO localization skymap of a burst
  15. GRB 251028B: Glowbug gamma-ray detection
  16. GRB 251028A: Glowbug gamma-ray detection
  17. GRB 251028B: CALET Gamma-Ray Burst Monitor detection
  18. Fermi GRB 251028B: Global MASTER-Net observations report
  19. GRB 251028B: Fermi GBM Final Localization Correction
  20. GRB251026B: PRIME H-band upper limit
  21. GRB 251028A: BALROG localization (Fermi Trigger 783314796 / GRB 251028143)
  22. GRB 251028A: Fermi GBM Final Real-time Localization
  23. GRB 251013C : 3.4-m telescope of Iranian National Observatory (INO340) optical observations
  24. GRB 251026B: Swift-XRT observations of GOTO25jgl/AT2025absf
  25. GRB 251025C: Glowbug gamma-ray detection
  26. Fermi-LAT Gamma-ray Observations of IceCube-251025A
  27. Konus-Wind detection of GRB 251022A
  28. GRB 251022A: SVOM/GRM observation
  29. GRB 251026B: Swift ToO observations
  30. Konus-Wind detection of GRB 251016A (short/hard)
  31. GRB 251026B: Tentative GOTO optical counterpart candidate
  32. GRB 251025C: CALET Gamma-Ray Burst Monitor detection
  33. Fermi GRB 251026B: Global MASTER-Net observations report
  34. Fermi GRB 251025C: Global MASTER-Net observations report
  35. GRB 251026B: Fermi GBM Final Localization
  36. GRB 251023A: SVOM/GRM observation
  37. GRB 251025C: Fermi GBM Final Real-time Localization
  38. Konus-Wind detection of GRB 251016B
  39. IceCube-251025A - IceCube observation of a high-energy neutrino candidate track-like event
  40. GRB 251003A: VLA Detection
  41. GRB 251022A: KAIT optical observations
  42. GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
  43. GRB 251022A: Swift-XRT detection of GOTO25iym
  44. GRB 251022A: GROWTH-India Telescope optical observations
  45. GRB 251022A: Fermi GBM Observation
  46. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  47. GRB 251023A: Glowbug gamma-ray detection
  48. IPN triangulation of GRB 251016B
  49. GRB 251013C: further SAO RAS optical observations
  50. GRB 251022A: COLIBRÍ optical observations
  51. GRB 251013C: ISON-Castelgrande observatory optical observations
  52. GRB 251022A: MASTER OT detection
  53. GRB 251022A: DDOTI Optical Detection
  54. Fermi GRB 251023A: Global MASTER-Net observations report
  55. GRB 251022A: GOTO optical counterpart detection
  56. GRB 251023A: Fermi GBM Final Localization Correction
  57. GRB 251022A: Fermi-LAT detection
  58. GRB 251016B: Fermi GBM Detection
  59. GRB 251022A: Tiled Swift observations
  60. GRB 251022A: Fermi GBM Final Real-time Localization
  61. GRB 251021A/EP251021b: Fermi-GBM Sub-Threshold Detection
  62. GRB 251016A: SVOM/ECLAIRs refined analysis
  63. Fermi-LAT gamma-ray observations of IceCube-251018A
  64. GRB 251016A: Fermi GBM Observation
  65. GRB 251018A: Fermi GBM Observation
  66. GRB 251018A: BOOTES-5 and BOOTES-7 early optical detections
  67. Fermi trigger No 782500909: Global MASTER-Net observations report
  68. GRB 251016A: HXMT/HE detection
  69. GRB 251016A: Swift/UVOT Detection
  70. IceCube-251018A - IceCube observation of a high-energy neutrino candidate track-like event
  71. GRB 251016A: VLT/FORS2 Optical Observation
  72. GRB 251018A: MASTER OT detection
  73. GRB 251018A: Fermi GBM Final Real-time Localization
  74. GRB 251011A: Fermi GBM Observation
  75. GRB 251013C: Liverpool Telescope observations
  76. GRB 251013C: Leavitt Observatory optical photometry
  77. Fermi GRB 251016B: Global MASTER-Net observations report
  78. GRB 251016A: AstroSat CZTI detection of a short burst
  79. GRB 251016B: AstroSat CZTI detection
  80. GRB 251016A: CALET Gamma-Ray Burst Monitor detection
  81. GRB 251016B: CALET Gamma-Ray Burst Monitor detection
  82. GRB 251013C: JinShan observations of the non-thermal rebrightening of the optical counterpart
  83. GRB 251016B: Fermi GBM Final Real-time Localization
  84. GRB 251016A: BOOTES-6/DPRT optical upper limit
  85. GRB 251016A: Glowbug gamma-ray detection of a short burst
  86. GRB 251013C: VLA detection
  87. Fermi GRB 251016A: Global MASTER-Net observations report
  88. GRB 251016A: Fermi GBM Final Localization
  89. GRB 251016A: SVOM detection of a short burst
  90. GRB 251014B: PRIME J-band upper limit
  91. GRB 251013C: Kilonova-Catcher optical afterglow detection
  92. Fermi-LAT Gamma-ray Observations of IceCube-251014A
  93. GRB 251013D: Swift/UVOT Observations
  94. GRB 251013C: Swift/UVOT Detection
  95. Konus-Wind detection of GRB 251007A
  96. Fermi Gamma-ray Burst Monitor trigger 782237334/251015673 is not a GRB
  97. GRB 251015A: Fermi GBM Final Real-time Localization
  98. GRB 251013C: SVOM/ECLAIRs refined analysis
  99. GRB 251013D: Swift-XRT observations
  100. GRB 251014B: Swift-XRT observations

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