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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"

28233 results found.

  1. EP260210a: Optical upper limits with Kinder observations
  2. GRB 260210A: Glowbug gamma-ray detection
  3. GRB 260208C: AstroSat CZTI detection
  4. EP260210a: COLIBRÍ optical upper limit
  5. EP260210a: SVOM/C-GFT upper limit
  6. EP260210a: Einstein Probe detection of an X-ray transient
  7. GRB 260207B: AstroSat CZTI detection
  8. GRB 260208C: SVOM/GRM observation
  9. GRB 260204A: Swift-XRT afterglow detection
  10. GRB 260208B: AstroSat CZTI detection of a bright long burst
  11. GRB260208A: Liverpool Telescope optical follow-up observations
  12. GRB 260208A: Glowbug gamma-ray detection
  13. GRB 260208A: NuSTAR detection of prompt emission
  14. GRB 260208A: Fermi GBM Observation
  15. Fermi GRB 260209A: Global MASTER-Net observations report
  16. GRB 260208B: Swift-XRT observations
  17. GRB 260131A/B: continued Mondy optical observations
  18. GRB 260204A: Swift/UVOT Upper Limits
  19. GRB 260208B: COLIBRÍ optical observations
  20. GRB 260208A: Mondy optical observations
  21. GRB 260208A: 1.3m DFOT optical detection
  22. GRB 260208A: COLIBRÍ optical observations
  23. GRB 260208B: EP-FXT observation
  24. Fermi GRB 260208C: Global MASTER-Net observations report
  25. GRB 260208B: SVOM/VT optical candidate
  26. GRB 260208A: GECAM-B observation of a bright burst
  27. GRB 260208A: Zwicky Transient Facility Follow-Up of a Fermi GRB (Trigger 792220053)
  28. GRB 260208A: SVOM/VT optical observation
  29. Fermi GRB 260208D: Global MASTER-Net observations report
  30. GRB 260208A: Swift-XRT observations
  31. GRB 260208B: SVOM/GRM observation of a bright burst
  32. GRB 260208B: Fermi GBM Detection
  33. LAT GRB 260208B: Global MASTER-Net observations report
  34. GRB 260208A : MASTER bright optical transient inside retracted Fermi error-box
  35. GRB 260208B: BALROG localization (Fermi Trigger 792237169 / GRB 260208412)
  36. Fermi GRB 260208A: Global MASTER-Net observations report
  37. GRB 260207B: Fermi GBM Detection of a Short Burst with Extended Emission
  38. GRB 260131A/B: Mondy and Terskol optical observations
  39. Fermi GRB 260207B: Global MASTER-Net observations report
  40. GRB 260206A: Swift-XRT observations
  41. Fermi trigger No 792135758: Global MASTER-Net observations report
  42. GRB 260206A (or XRB from 4U 0513-40): MAXI/GSC detection
  43. GRB 260204A: Swift-XRT observations
  44. GRB 260204A: SVOM/VT optical candidate
  45. GRB 260204A : MASTER Global robotic net optical observations
  46. Fermi GBM Sub-Threshold Detection of GRB 260204A
  47. GRB 260204A: LCO optical upper limits
  48. EP260110a: Late GTC/EMIR near-infrared observations
  49. GRB 260121A: 239Alferov CubeSat detection
  50. GRB 260131A: KAIT optical observations
  51. GRB 251230A: MeerLICHT afterglow detection
  52. GRB 260131A/B: GTC/OSIRIS+ redshift confimation
  53. GRB 260130A: Insight-HXMT/HE detection
  54. GRB 260131A/B (AT2026bwg): J-band observations by SYSU 80cm infrared telescope
  55. GRB 260131A/B (AT2026bwg): COLIBRÍ further optical observations
  56. GRB 260127A: GECAM-B observation
  57. EP260131a: Liverpool Telescope optical upper limits
  58. EP260131a: COLIBRÍ further observations
  59. EP260131a: SVOM/VT optical observation
  60. EP260131a: Xinglong optical upper limit
  61. GRB 260131A/B (AT2026bwg): COLIBRÍ optical observations and confirmation of fading
  62. GRB 260131A/B: Fermi GBM Observation
  63. EP260131a: COLIBRÍ observations of slow optical fading
  64. EP260131a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  65. EP260131a: NOT early detection of the counterpart in "rapid response mode"
  66. GRB 260131B: MAXI/GSC detection
  67. EP260131a: COLIBRÍ optical observations of the counterpart
  68. EP260131a: Las Cumbres detection of an optical counterpart
  69. GRB 260127B: AstroSat CZTI detection
  70. GRB 260130A: Fermi GBM Detection
  71. EP260131a: Einstein Probe detection of an X-ray transient
  72. GRB 260127B: Fermi GBM Detection
  73. EP260128a / GRB 260128A: COLIBRÍ optical upper limit
  74. Fermi GRB 260130A: Global MASTER-Net observations report
  75. Fermi GRB 260129A: Global MASTER-Net observations report
  76. GRB 260128B: LCO optical upper limits
  77. GRB 260128B: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  78. EP260128a: J band upper limit by SYSU 80cm infrared telescope
  79. GRB 260127A: Swift-BAT refined analysis
  80. GRB 260127B: Swift-XRT observations
  81. GRB 260127A: INASAN-Kislovodsk, SAO RAS, and Terskol K-800 optical observations
  82. GRB 260128A / EP260128a: Fermi-GBM Sub-Threshold Detection
  83. EP260128a: NOT optical counterpart candidate
  84. EP260128a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  85. EP260128a: Liverpool Telescope optical observations and possible counterpart
  86. EP260128a: LCO optical upper limits
  87. EP260128a: Global MASTER-Net observations report
  88. EP260128a: Einstein Probe detection of an X-ray transient
  89. Fermi GRB 260127A: Global MASTER-Net observations report
  90. GRB 260127A: Fermi GBM Observation
  91. IceCube-260125A: Upper limits from a search for additional neutrino events in IceCube
  92. GRB 260127A: COLIBRÍ optical observations
  93. EP260126a: Seimei/TriCCS optical upper limit
  94. GRB 260127A : MITSuME Akeno optical afterglow candidate detection
  95. GRB 260127A: Swift-XRT refined Analysis
  96. GRB 260127A: SVOM/C-GFT optical observations
  97. GRB 260127A: Enhanced Swift-XRT position
  98. Fermi GRB 260127B: Global MASTER-Net observations report
  99. Swift GRB 260127A: Global MASTER-Net observations report
  100. GRB 260127A: LCO optical afterglow discovery

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