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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"

28200 results found.

  1. GRB 260127A: Swift detection of a burst
  2. GRB 260127A: Fermi GBM Final Real-time Localization
  3. GRB 260125A: Swift-XRT observations
  4. EP260126a: EP-FXT follow-up observation
  5. EP260126a: Liverpool Telescope optical upper limits
  6. EP260126a: Further NOT optical upper limits
  7. EP260126a: Einstein Probe detection of a fast X-ray transient
  8. Konus-Wind detection of GRB 260120B
  9. GRB 260125A: Swift ToO observations
  10. GRB 260125A: GOTO candidate optical counterpart
  11. IceCube-260125A - IceCube observation of a high-energy neutrino candidate track-like event
  12. GRB 260125B: Fermi GBM Final Real-time Localization
  13. GRB 260125A: Fermi GBM Final Real-time Localization
  14. GRB 260114A: SVOM/VT optical upper limits
  15. GRB 260120A: AstroSat CZTI detection
  16. GRB 260120B: AstroSat CZTI detection
  17. GRB 260114A: Insight-HXMT/HE detection
  18. GRB 260122B: Swift detection of a burst
  19. GRB 260122A: Fermi GBM Final Real-time Localization
  20. EP260119a: Xinglong optical upper limit
  21. GRB 260120B: Swift-XRT refined Analysis
  22. GRB 251122A / EP251122a: VLT/X-shooter host redshift z = 1.765
  23. GRB 260120B: Fermi GBM Observation
  24. EP260105a: GTC/HiPERCAM optical observations
  25. GRB 260120B: Swift/UVOT Detection
  26. GRB 260120B: COLIBRÍ optical upper limits
  27. GRB 260120B: Enhanced Swift-XRT position
  28. GRB 260120B: SVOM/C-GFT optical counterpart detection
  29. GRB 260120C: Fermi GBM Final Real-time Localization
  30. GRB 260101A: 239Alferov CubeSat detection
  31. GRB 260120B: Swift detection of a burst
  32. GRB 260120B: Fermi GBM Final Real-time Localization
  33. EP260119A: Mondy I-Band Observations
  34. GRB 260114A: Swift/UVOT Upper Limits
  35. EP260119a: Liverpool Telescope optical follow-up observations
  36. Trigger 1442421: Swift detection of HMXB 1A 1118-61
  37. EP260119a: KAIT optical observations
  38. GRB 260120A: Fermi GBM Final Real-time Localization
  39. EP260119a: update of EP-FXT follow-up observation
  40. EP260116a: COLIBRÍ detection of a fading optical source
  41. GRB 260117A: Swift-XRT afterglow detection
  42. GRB 260115A: AstroSat CZTI detection
  43. EP260119a: LCO optical observations
  44. GRB 260117A: ZTSh optical upper limit
  45. EP260119a: preliminary result from the EP-FXT observation
  46. GRB 260110A: SVOM detection of a burst through offline search
  47. EP260119a: EP-WXT detection of a fast X-ray transient
  48. GRB 260117A: SVOM/COLIBRÍ (FM-GFT) optical observations
  49. Swift trigger on the HMXB 1A 1118-61
  50. GRB 260117A: SVOM/VT optical candidate
  51. GRB 260117A: SVOM/C-GFT upper limit
  52. GRB 260117A: Swift-XRT observations
  53. GRB 260117A: Swift ToO observations
  54. GRB 260117A: SVOM detection of a long faint burst
  55. Swift triggered on the HMXB 1A 1118-61
  56. EP260116A: 1.3m DFOT optical upper limit
  57. GRB 260114A: VLT/MUSE spectroscopic observations
  58. GRB 260111A: COLIBRÍ fading of the optical counterpart candidate
  59. EP260116a: Xinglong optical upper limit
  60. EP260116a: Einstein Probe detection of an X-ray transient
  61. GRB 260114A: VLT/HAWK-I further near-infrared upper limits
  62. IceCube-260115A - IceCube observation of a high-energy neutrino candidate track-like event
  63. GRB 260115A: Fermi GBM Final Real-time Localization
  64. GRB260114A: STEP/T80S optical limits
  65. GRB 251222A: radio detection with the VLA
  66. GRB 260114A: VLT/HAWK-I near-infrared upper limits
  67. Konus-Wind detection of GRB 260114A
  68. GRB 260114A: Swift-XRT refined Analysis
  69. GRB 260114A: 6 GHz VLA observations
  70. GRB 260114A: VLT/X-shooter redshift of the putative host galaxy
  71. GRB 260114A : MITSuME Akeno optical upper limits
  72. GRB 260114A: COLIBRÍ optical upper limits
  73. GRB 260114A: TNG NIR upper limit
  74. GRB 260114A: NOT optical observations
  75. Konus-Wind detection of GRB 251230A / EP251230a
  76. GRB 260114A: Mondy optical observations
  77. GRB 260114A: GMG Optical Observation
  78. GRB 260114A: Swift detection of a short burst
  79. GRB 260114A: Fermi GBM Final Real-time Localization
  80. EP260110a: TRT optical upper limits
  81. Konus-Wind detection of GRB 260101A
  82. GRB 260111A: Swift-XRT observations
  83. Swift Trigger 1439093: is probably not GRB 260113A
  84. GRB 260111A: COLIBRÍ optical afterglow candidate
  85. Swift Trigger 1434591 is not a GRB
  86. GRB 260112B: Fermi GBM Final Real-time Localization
  87. GRB 260111A: Swift ToO observations
  88. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  89. GRB 260112A: Fermi GBM Final Real-time Localization
  90. IceCube-260111A - IceCube observation of a high-energy neutrino candidate track-like event
  91. GRB 260111A: Fermi GBM Final Real-time Localization
  92. Swift trigger 1436759 is not an astrophysical event
  93. EP260110a: BOOTES-5/JGU optical upper limit
  94. EP260110a: Einstein Probe detection of an X-ray transient
  95. GRB 260109C: LCO optical upper limits
  96. EP260105b / GRB 260105C : Fermi-GBM Sub-Threshold Detection
  97. Swift Trigger 1434591: possible GRB 260109C
  98. GRB 260109B: Fermi GBM Final Real-time Localization
  99. GRB 260102A: Swift-XRT afterglow detection
  100. GRB 260109A: Fermi GBM Final Real-time Localization

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