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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"

36386 results found.

  1. GRB 251025B: SVOM detection of a burst
  2. GRB 251025A (sb25102501): Likely a stellar flare by SVOM/VT
  3. GRB 251025A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  4. GRB 251025A: SVOM/VT VHF optical upper limit
  5. GRB 251025A: SVOM detection of a faint burst
  6. GRB 251003A: VLA Detection
  7. GRB 251024A: Enhanced Swift-XRT position
  8. GRB 251023C: Glowbug gamma-ray detection
  9. GRB 251024A: LCOGT Optical Afterglow Detection
  10. GRB 251022A: KAIT optical observations
  11. GRB 251024A: Swift detection of a burst
  12. Swift GRB 251024A: Global MASTER-Net observations report
  13. GRB 251023B / EP251023b: COLIBRÍ Confirmation of the Fading Nature of the Optical Candidate
  14. GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
  15. GRB 251023B: OHP/T193 optical observations
  16. EP251023a: OHP/T193 optical observations
  17. GRB 251023C: AstroSat CZTI detection
  18. EP251023b/GRB 251023B: JinShan optical observation
  19. GRB 251022A: Swift-XRT detection of GOTO25iym
  20. EP251023b/GRB 251023B : Einstein Probe detection of a fast X-ray transient
  21. GRB 251023C: CALET Gamma-Ray Burst Monitor detection
  22. GRB 251022A: GROWTH-India Telescope optical observations
  23. GRB 251023C: Swift/BAT-GUANO localization skymap of a burst
  24. GRB 251022A: Fermi GBM Observation
  25. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  26. GRB 251023A: Glowbug gamma-ray detection
  27. GRB 251023B: Glowbug gamma-ray detection
  28. GRB 251023B / EP#01709247298: COLIBRÍ optical counterpart candidate
  29. IPN triangulation of GRB 251016B
  30. GRB 251023B: CALET Gamma-Ray Burst Monitor detection
  31. EP#01709247298: Swift-XRT counterpart detection
  32. GRB 251013C: further SAO RAS optical observations
  33. GRB 251022A: COLIBRÍ optical observations
  34. GRB 251013C: ISON-Castelgrande observatory optical observations
  35. GRB 251022A: MASTER OT detection
  36. GRB 251022A: DDOTI Optical Detection
  37. EP251021b/GRB 251021A: SVOM/VT optical candidate
  38. GRB 251023B / MAXI J0451+122: MAXI/GSC detection
  39. Fermi GRB 251023A: Global MASTER-Net observations report
  40. GRB 251022A: GOTO optical counterpart detection
  41. GRB 251023A: Fermi GBM Final Localization Correction
  42. GRB 251022A: Fermi-LAT detection
  43. GRB 251016B: Fermi GBM Detection
  44. GRB 251022A: Tiled Swift observations
  45. GRB 251022A: Fermi GBM Final Real-time Localization
  46. GRB 251021A/EP251021b: Fermi-GBM Sub-Threshold Detection
  47. GRB 250911A: MAXI/GSC detection
  48. GRB 251016A: SVOM/ECLAIRs refined analysis
  49. GRB 251017A : RAPAS follow-up observations
  50. IceCube-251018A: Upper limits from a search for additional neutrino events in IceCube
  51. GRB 251017A: COLIBRÍ optical observations of a late plateau
  52. GRB 251017A: Swift-BAT refined analysis
  53. GRB 251016A: Fermi GBM Observation
  54. GRB 251018A: Fermi GBM Observation
  55. GRB 251018A: BOOTES-5 and BOOTES-7 early optical detections
  56. GRB 251018A: Swift-XRT refined Analysis
  57. GRB 251018A: Enhanced Swift-XRT position
  58. GRB 251016A: HXMT/HE detection
  59. GRB 251016A: Swift-XRT afterglow detection
  60. GRB 251017A: Swift/UVOT Detection
  61. GRB 251016A: Swift/UVOT Detection
  62. GRB 251018A: Swift/UVOT Detection
  63. GRB 251017A: VLT/MUSE spectroscopic redshift z = 4.327
  64. GRB 251016A: VLT/FORS2 Optical Observation
  65. GRB 251017A: COLIBRÍ photometric redshift
  66. GRB 251017A: Swift-XRT refined Analysis
  67. GRB 251018A: MASTER OT detection
  68. GRB 251018A: TRT optical afterglow detection
  69. Swift GRB 251018A: Global MASTER-Net observations report
  70. GRB 251018A: Swift detection of a burst with an optical counterpart
  71. GRB 251018A: Fermi GBM Final Real-time Localization
  72. GRB 251017A: SVOM/VT optical observation
  73. GRB 251011A: Fermi GBM Observation
  74. GRB 251017A: OHP/T193 i-band observations
  75. GRB 251013C: OHP/T193 third epoch optical observations and detected rebrightening
  76. GRB 251017A: J-band detection with WINTER
  77. GRB 251017A: Glowbug gamma-ray detection
  78. GRB 251013C: Liverpool Telescope observations
  79. GRB 251013C: Leavitt Observatory optical photometry
  80. Fermi GRB 251016B: Global MASTER-Net observations report
  81. GRB 251017A: JinShan observations of the optical afterglow
  82. Swift GRB 251017A: Global MASTER-Net observations report
  83. GRB 251017A : MITSuME Akeno optical afterglow candidate detection
  84. Swift Trigger 1404295 is not a GRB
  85. GRB 251016A: AstroSat CZTI detection of a short burst
  86. GRB 251017A: Enhanced Swift-XRT position
  87. GRB 251017A: COLIBRÍ Early Afterglow Detection
  88. GRB 251016B: AstroSat CZTI detection
  89. GRB 251017A: BOOTES-5/JGT early optical afterglow detection
  90. GRB 251017A: Swift detection of a burst with an optical counterpart
  91. GRB 251016A: CALET Gamma-Ray Burst Monitor detection
  92. GRB 251016B: CALET Gamma-Ray Burst Monitor detection
  93. GRB 251013C: JinShan observations of the non-thermal rebrightening of the optical counterpart
  94. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) observations of a strong and late rebrightening of the optical counterpart
  95. GRB 251007B: Swift-BAT refined analysis
  96. GRB 251016B: Fermi GBM Final Real-time Localization
  97. GRB 251014D: Swift-BAT refined analysis
  98. GRB 251016A: BOOTES-6/DPRT optical upper limit
  99. GRB 251016A: Glowbug gamma-ray detection of a short burst
  100. GRB 251013C: VLA detection

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