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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"

41734 results found.

  1. Fermi-LAT Gamma-ray Observations of IceCube-260622A
  2. EP260628a: EP-FXT follow-up observation
  3. GRB 260629A: Fermi GBM Final Real-time Localization
  4. Fermi GRB 260628A: Global MASTER-Net observations report
  5. EP260628a: EP-WXT detection of a fast X-ray transient
  6. GRB 260628A: Fermi GBM Final Real-time Localization
  7. The EP-WXT trigger 01709272671 is likely a flaring star
  8. EP260626a: further Liverpool Telescope optical upper limits
  9. EP260626a: EP-FXT follow-up observation
  10. EP260626a: COLIBRÍ optical upper limit
  11. EP260626a: Liverpool Telescope upper limits
  12. EP260626a: EP-WXT detection of a fast X-ray transient
  13. Konus-Wind detection of GRB 260623B / EP260623a
  14. EP260623a: TNG NIR afterglow detection
  15. GRB 260618A: Fermi GBM Observation
  16. EP260623a: FTW optical and NIR observations
  17. GRB 260619A: SVOM/ECLAIRs refined analysis
  18. EP260623a: Liverpool Telescope optical observations
  19. Konus-Wind detection of GRB 260618B
  20. GRB 260624A: Fermi GBM Final Real-time Localization
  21. EP260623a:refined analysis of the EP-WXT and EP-FXT observation
  22. EP260623a: WINTER J-band observations
  23. GRB 260617A: Glowbug gamma-ray detection of a short burst
  24. IceCube-260622A: Upper limits from a search for additional neutrino events in IceCube
  25. EP260623a: Optical follow-up observations with Kinder
  26. EP260623a: FRAM-ORM detection of the optical afterglow rise, peak and decay
  27. GRB 260623A: Fermi GBM Final Real-time Localization
  28. EP260623a: SVOM/VT optical observations
  29. EP260623a: TRT optical observations
  30. EP260623a: REM optical/NIR afterglow detection
  31. EP 260623a: COLIBRÍ optical observations
  32. GRB 260616B/EP260616a: Insight-HXMT/HE detection
  33. EP260623a: OSIRIS+/GTC redshift z = 0.703
  34. EP260623a: Las Cumbres discovery of the optical counterpart
  35. EP260623a: Einstein Probe detection of an X-ray transient
  36. GRB 260614B: EP-FXT follow-up observation
  37. IceCube-260622A - IceCube observation of a high-energy neutrino candidate track-like event
  38. GRB 260618C: SVOM/ECLAIRs detection of a possible burst through on-ground search
  39. EP260618a: Liverpool Telescope optical observations
  40. GRB 260619A: NOT optical observations
  41. GRB 260618B: LCO optical observations
  42. The EP-WXT trigger 01709271197 is likely a flaring star
  43. EP260618a: JinShan optical observations
  44. GRB 260616B/EP260616a: SVOM/GRM detection of a burst
  45. GRB 260618B: Fermi GBM Observation
  46. IceCube-Cascade 260618A: Upper limits from a search for additional neutrino events in IceCube
  47. GRB 260619A: TRT optical counterpart confirmation
  48. GRB 260610B: Further GRANDMA Optical Observations and re-brightening detection
  49. GRB 260604B: 239Alferov CubeSat detection
  50. GRB 260604A: 239Alferov CubeSat detection
  51. GRB 260610B: VLT/FORS2 spectroscopic observation suggests the non-thermal nature of the optical rebrightening
  52. GRB 260619A: SVOM/VT optical counterpart confirmation
  53. Fermi-LAT Gamma-ray Observations of IceCube-260610A
  54. GRB 260618B: SVOM/VT optical candidate
  55. GRB 260618B: SVOM/VT optical candidate (duplicate Submission of 45001)
  56. GRB 260619A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  57. Konus-Wind detection of GRB 260617A
  58. GRB 260616B: AstroSat CZTI detection
  59. GRB 260616A: AstroSat CZTI detection
  60. GRB 260616A: SVOM/GRM observation
  61. EP260618a: OHP/T193 optical observations
  62. GRB 260610B/AT2026owq: 1.3m DFOT optical rebrightening detection
  63. GRB 260619A: Kilonova-Catcher optical upper limit
  64. EP260618a: EP-FXT follow-up observation
  65. EP260618a: LCO optical counterpart confirmation
  66. GRB 260617A: CALET Gamma-Ray Burst Monitor detection
  67. EP260618a: COLIBRÍ optical counterpart candidate
  68. GRB 260616A: NuSTAR detection of prompt emission
  69. GRB 260614B: NuSTAR detection of prompt emission
  70. GRB 260619A: SVOM possible detection of a faint burst
  71. IceCube-260610A: Upper limits from a search for additional neutrino events in IceCube
  72. GRB 260618B: Fermi-LAT detection
  73. GRB 260610B/AT 2026owq: FTW optical and NIR observations
  74. GRB 260616A: Insight-HXMT detection
  75. GRB 260618B: Fermi GBM Final Real-time Localization
  76. EP260618a: EP-WXT detection of an X-ray transient
  77. GRB 260610B: AbAO optical observations
  78. EP260616a/GRB 260616B: EP-FXT follow-up observation
  79. GRB 260506B: cubesat Avion detection
  80. GRB 260616C: GECAM-B observation of a burst
  81. GRB 260618A: Fermi GBM Final Real-time Localization
  82. GRB 260617A: Fermi GBM Detection
  83. GRB 260616A: Fermi GBM Observation
  84. GRB 260617A: Fermi GBM Final Real-time Localization
  85. Konus-Wind detection of GRB 260616B/EP260616a
  86. Konus-Wind detection of GRB 260616A
  87. GRB 260616B: CALET Gamma-Ray Burst Monitor detection
  88. EP260616a/GRB260616B: COLIBRÍ optical upper limit
  89. GRB 260616A: GECAM-B observation
  90. GRB 260610B / AT2026owq: SAO RAS optical observations of possible re-brightening
  91. GRB 260429A: cubesat Avion detection
  92. GRB260616C: MAXI/GSC detection
  93. GRB 260616A: Fermi-LAT detection
  94. GRB 260610B / AT 2026owq: Liverpool Telescope confirmation of continuing optical rebrightening
  95. GRB 260610B / AT 2026owq: COLIBRÍ further observations and confirmation of the rebrigthening
  96. GRB 260614A: AstroSat CZTI detection
  97. EP260616a: EP-WXT detection of a fast X-ray transient
  98. GRB 260610B / AT 2026owq: Possible re-brightening identified from Pan-STARRS observations
  99. The EP-WXT trigger 01709270148 is likely a flaring star
  100. GRB 260616B: Fermi GBM Detection

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