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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

26535 results found.

  1. GRB 260125A: NOT optical observations on GOTO26acv / AT 2026bjf
  2. Konus-Wind detection of GRB 260120B
  3. GRB 251222A: SVOM/ECLAIRs refined analysis
  4. GRB 260125A: GOTO candidate optical counterpart
  5. IceCube-260125A - IceCube observation of a high-energy neutrino candidate track-like event
  6. GRB 260114A: SVOM/VT optical upper limits
  7. GRB 260120A: AstroSat CZTI detection
  8. GRB 260122B: Swift-BAT refined analysis
  9. GRB 260120B: SVOM/GRM observation
  10. GRB 260120A: GECAM-B observation
  11. GRB 260120B: AstroSat CZTI detection
  12. GRB 260114A: Insight-HXMT/HE detection
  13. GRB 260122B: Swift detection of a burst
  14. IceCube-260115A: No Candidate Transients from the Zwicky Transient Facility
  15. EP260119a: Xinglong optical upper limit
  16. GRB 260120B: Swift-BAT refined analysis
  17. EP260116a: COLIBRÍ further observations
  18. GRB 251122A / EP251122a: VLT/X-shooter host redshift z = 1.765
  19. GRB 260120B: Fermi GBM Observation
  20. EP260105a: GTC/HiPERCAM optical observations
  21. GRB 260120B: Swift/UVOT Detection
  22. GRB 260120B: COLIBRÍ optical upper limits
  23. SVOM GRB260121.06: Global MASTER-Net observations report
  24. GRB 260120B: Enhanced Swift-XRT position
  25. GRB 260120B: SVOM/C-GFT optical counterpart detection
  26. GRB 260101A: 239Alferov CubeSat detection
  27. EP260116a: COLIBRÍ observations of a tentative optical rebrightening
  28. GRB 260120B: Swift detection of a burst
  29. EP260119A: Mondy I-Band Observations
  30. EP260119a: Liverpool Telescope optical follow-up observations
  31. GRB 251202A: further radio observations with the VLA
  32. EP260119A: GTC/OSIRIS+ spectroscopic redshift z = 5.47
  33. EP260119a: SVOM/VT optical observation
  34. EP260119a: update of EP-FXT follow-up observation
  35. SVOM GRB260119.92: Global MASTER-Net observations report
  36. SVOM GRB260119.92: Global MASTER-Net observations report
  37. SVOM GRB260119.90: Global MASTER-Net observations report
  38. EP260116a: COLIBRÍ detection of a fading optical source
  39. GRB 251208D: SVOM/ECLAIRs refined analysis
  40. GRB 251208D: SVOM/ECLAIRs refined analysis
  41. GRB 260117A: Swift-XRT afterglow detection
  42. EP260119a: COLIBRÍ photometric redshift z ≈ 5.6
  43. GRB 260115A: AstroSat CZTI detection
  44. EP260119a: LCO optical observations
  45. GRB 260117A: ZTSh optical upper limit
  46. EP260119a: COLIBRÍ optical counterpart candidate
  47. EP260119a: preliminary result from the EP-FXT observation
  48. GRB 260110A: SVOM detection of a burst through offline search
  49. EP260119a: EP-WXT detection of a fast X-ray transient
  50. GRB 260117A: SVOM/COLIBRÍ (FM-GFT) optical observations
  51. SVOM GRB260117.82: Global MASTER-Net observations report
  52. Swift trigger on the HMXB 1A 1118-61
  53. GRB 260117A: SVOM/VT optical candidate
  54. GRB 260117A: SVOM/C-GFT upper limit
  55. GRB 260117A: Swift-XRT observations
  56. GRB 260117A: Swift ToO observations
  57. GRB 260117A: SVOM detection of a long faint burst
  58. EP 260116a: COLIBRÍ optical upper limit
  59. Swift triggered on the HMXB 1A 1118-61
  60. GRB 260115A: GECAM-B observation
  61. FRB 20251229A: COLIBRÍ further inspection of the updated localization
  62. EP260116A: 1.3m DFOT optical upper limit
  63. GRB 260114A: VLT/MUSE spectroscopic observations
  64. GRB 260111A: COLIBRÍ fading of the optical counterpart candidate
  65. EP260116a: Xinglong optical upper limit
  66. EP260116a: Einstein Probe detection of an X-ray transient
  67. GRB 260114A: VLT/HAWK-I further near-infrared upper limits
  68. IceCube-260115A - IceCube observation of a high-energy neutrino candidate track-like event
  69. GRB260114A: STEP/T80S optical limits
  70. GRB 251222A: radio detection with the VLA
  71. GRB 260114A: VLT/HAWK-I near-infrared upper limits
  72. Konus-Wind detection of GRB 260114A
  73. GRB 260114A: 6 GHz VLA observations
  74. GRB 260114A: VLT/X-shooter redshift of the putative host galaxy
  75. GRB 260114A : MITSuME Akeno optical upper limits
  76. GRB 260114A: COLIBRÍ optical upper limits
  77. GRB 260114A: TNG NIR upper limit
  78. GRB 260114A: NOT optical observations
  79. Konus-Wind detection of GRB 251230A / EP251230a
  80. GRB 260114A: SVOM/GRM observation of a short burst
  81. GRB 260114A: GECAM-B observation of a short burst
  82. GRB 260114A: Fermi GBM observation
  83. GRB 260112B: GECAM-B observation
  84. GRB 260114A: Swift detection of a short burst
  85. EP-WXT trigger 01709251266: SVOM/C-GFT confirmation of a stellar flare
  86. EP260110a: TRT optical upper limits
  87. Konus-Wind detection of GRB 260101A
  88. Swift Trigger 1439093: is probably not GRB 260113A
  89. GRB 260111A: COLIBRÍ optical afterglow candidate
  90. GRB 260111A: GECAM-B observation of a burst
  91. GRB 260111A: Fermi GBM Observation
  92. GRB 260111A: GOTO optical upper limits
  93. GRB 251230A: Mondy Optical Observations
  94. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  95. EP260110a: SVOM/VT optical upper limits
  96. IceCube-260111A - IceCube observation of a high-energy neutrino candidate track-like event
  97. EP260110a: KAIT optical upper limit
  98. EP260110a: refined analysis of the EP-WXT and EP-FXT observations
  99. EP 260110a: COLIBRÍ optical observations
  100. EP260110a: SVOM/C-GFT upper limit

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