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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"

11632 results found.

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

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