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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"

28207 results found.

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

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