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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"

36000 results found.

  1. GRB 260207B: Fermi GBM Detection of a Short Burst with Extended Emission
  2. GRB 260207A : MASTER optical counterpart discovery
  3. GRB 260131A/B: Mondy and Terskol optical observations
  4. Fermi GRB 260207B: Global MASTER-Net observations report
  5. GRB 260206A: Swift-XRT observations
  6. GRB 260207B: Fermi GBM Final Real-time Localization
  7. GRB 260207A: Fermi GBM Final Localization
  8. EP260131a: VLA detection
  9. GRB 260206A: Tiled Swift observations
  10. GRB 260206A (or XRB from 4U 0513-40): MAXI/GSC detection
  11. GRB 260204A: SVOM/VT confirms fading of the optical afterglow
  12. GRB 260204A: Swift-XRT observations
  13. GRB 260204A: LCO optical afterglow detection
  14. GRB 260204A: SVOM/VT optical candidate
  15. GRB 260204A : MASTER Global robotic net optical observations
  16. Fermi GBM Sub-Threshold Detection of GRB 260204A
  17. GRB 260204A: GOTO optical upper limit
  18. GRB 260204A: LCO optical upper limits
  19. GRB 260204B: Fermi GBM Final Real-time Localization
  20. GRB 260204A: SVOM detection of a burst
  21. GRB 260121A: 239Alferov CubeSat detection
  22. Konus-Wind detection of GRB 260121A
  23. GRB 260131A/B: OHP/T193 optical observations
  24. GRB 260131A: KAIT optical observations
  25. GRB 251230A: MeerLICHT afterglow detection
  26. GRB 260131A: FTW optical and NIR observations
  27. GRB 260131A/AT2026bwg: Observations by the Zwicky Transient Facility
  28. GRID detection of GRB 260131A/B
  29. GRB 260131A/B: GTC/OSIRIS+ redshift confimation
  30. GRB 260130A: Insight-HXMT/HE detection
  31. GRB 260130A: GECAM-B observation of a short burst
  32. GRB 260131A/B (AT2026bwg): J-band observations by SYSU 80cm infrared telescope
  33. GRB 260131A/B: EP/FXT X-ray afterglow detection
  34. GRB 260131A/B (AT2026bwg): COLIBRÍ further optical observations
  35. GRB 260127B: Insight-HXMT/HE detection
  36. GRB 260127B: GECAM-B observation of a short burst
  37. GRB 260127A: GECAM-B observation
  38. GRB 260131A: NOT spectroscopic redshift z = 1.434
  39. Konus-Wind detection of GRB 260128A / EP260128a
  40. GRB 260131A: Insight-HXMT/HE detection
  41. Konus-Wind detection of GRB 260131A/B
  42. GRB 260131A/B (AT2026bwg): COLIBRÍ optical observations and confirmation of fading
  43. GRB 260131A/B: GOTO candidate optical counterpart consistent with the MAXI localisation
  44. GRB 260131A/B: Fermi GBM Observation
  45. EP260131a: VLT/X-shooter spectroscopic redshift z = 0.937
  46. GRB 260131B: MAXI/GSC detection
  47. GRB 260131A: Fermi GBM Final Real-time Localization
  48. GRB 260127B: AstroSat CZTI detection
  49. GRB 260130A: Fermi GBM Detection
  50. GRB 260127B: Fermi GBM Detection
  51. EP260128a / GRB 260128A: COLIBRÍ optical upper limit
  52. Fermi GRB 260130A: Global MASTER-Net observations report
  53. EP260128a / GRB 260128A: NOT and TNG optical and NIR upper limits
  54. GRB 260130A: Fermi GBM Final Real-time Localization
  55. Fermi GRB 260129A: Global MASTER-Net observations report
  56. GRB 260128B: LCO optical upper limits
  57. GRB 260128B: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  58. IPN triangulation of GRB 260121A
  59. GRB 260127A: Swift-BAT refined analysis
  60. GRB 260129B: Fermi GBM Final Localization
  61. GRB 260128B: SVOM detection of a burst through offline search
  62. GRB 260129A: Fermi GBM Final Localization
  63. IPN triangulation of GRB 260127B (short)
  64. GRB 260127B: Swift-XRT observations
  65. GRB 260127A: INASAN-Kislovodsk, SAO RAS, and Terskol K-800 optical observations
  66. GRB 260128A / EP260128a: Fermi-GBM Sub-Threshold Detection
  67. Fermi GRB 260127A: Global MASTER-Net observations report
  68. GRB 260127A: Fermi GBM Observation
  69. GRB 260127A: COLIBRÍ optical observations
  70. GRB 260127A: NOT optical observations
  71. GRB 260127B: Swift ToO observations
  72. GRB 260127A : MITSuME Akeno optical afterglow candidate detection
  73. GRB 260127A: Swift-XRT refined Analysis
  74. GRB 260127B: GOTO candidate optical counterpart
  75. GRB 260127A: SVOM/C-GFT optical observations
  76. GRB 260127A: Enhanced Swift-XRT position
  77. Fermi GRB 260127B: Global MASTER-Net observations report
  78. GRB 260127B: Fermi GBM Final Real-time Localization
  79. GRB 260127A: Prompt enhanced Swift-XRT position
  80. Swift GRB 260127A: Global MASTER-Net observations report
  81. GRB 260127A: LCO optical afterglow discovery
  82. GRB 260127A: Swift detection of a burst
  83. GRB 260127A: Fermi GBM Final Real-time Localization
  84. GRB 260125A: Swift-XRT observations
  85. GRB 260125A: NOT optical observations on GOTO26acv / AT 2026bjf
  86. Konus-Wind detection of GRB 260120B
  87. GRB 251222A: SVOM/ECLAIRs refined analysis
  88. GRB 260125A: Swift ToO observations
  89. GRB 260125A: GOTO candidate optical counterpart
  90. Fermi GRB 260125B: Global MASTER-Net observations report
  91. GRB 260125B: Fermi GBM Final Real-time Localization
  92. GRB 260125A: Fermi GBM Final Real-time Localization
  93. GRB 260114A: SVOM/VT optical upper limits
  94. GRB 260120A: AstroSat CZTI detection
  95. GRB 260122B: Swift-BAT refined analysis
  96. GRB 260120B: SVOM/GRM observation
  97. GRB 260120A: GECAM-B observation
  98. GRB 260120B: AstroSat CZTI detection
  99. GRB 260114A: Insight-HXMT/HE detection
  100. GRB 260122B: Swift detection of a burst

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