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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"

4296 results found.

  1. GRB 261029C: AstroSat CZTI detection of a short burst
  2. EP261030a: GROWTH-India Telescope Upper Limit
  3. The EP-WXT trigger 01709321980: KAIT confirmation of a stellar flare
  4. GRB 261029A: Glowbug gamma-ray detection
  5. GRB 261026A: Mondy, SAO RAS and Terskol optical observations
  6. EP Alert 261030.22: Global MASTER-Net observations report
  7. GRB 261029A: ULL-ASTRO-MASTER observations with LCO 1-m telescope at Siding Spring Observatory
  8. GRB 261029A: Ondrejov D50 optical observations, possible rebrightening
  9. GRB 261029A: Liverpool Telescope observations
  10. GRB 261029A: Fermi GBM Observation
  11. GRB 261029A: CALET Gamma-Ray Burst Monitor detection
  12. GRB 261029B : AstroSat CZTI detection
  13. GRB 261029A / AT2026ahaw: r- and i-band optical follow-up with the PKU 60cm Telescope
  14. GRB 261029A : AstroSat CZTI detection
  15. GRB 261029A: EP-FXT follow-up observation
  16. GRB 261029A: LCO optical observations (correction to GCN 46082)
  17. GRB 261029A: SVOM/COLIBRÍ (FM-GFT) optical observations
  18. GRB 261029A: LCO optical observations
  19. GRB 261029A: NOT imaging and spectroscopic redshift z = 3.27
  20. GRB 261029A: KAIT optical observations
  21. GRB 261029B: Fermi GBM Final Real-time Localization
  22. GRB 261029A: GOTO optical counterpart candidate
  23. GRB 261029A: Fermi GBM Final Real-time Localization
  24. GRB 261026A: SVOM/VT optical observations
  25. Fermi GRB 261026B: Global MASTER-Net observations report
  26. GRB 261026A: SVOM/COLIBRÍ (FM-GFT) optical observations
  27. EP 261025a: COLIBRÍ optical upper limit
  28. EP261015a: VLA non-detection
  29. EP261015a: GSP multiband optical follow-up observations
  30. EP261015a: Follow-up with the 1.3m DFOT
  31. GRB 261020A: MAXI GSC detection
  32. GRB 261017A: R-band upper limit with the 1.3-m DFOT
  33. EP261015c: Einstein Probe detection of a fast X-ray transient
  34. GRB 261011A: Swift-BAT refined analysis
  35. MAXI GRB261012.23: Global MASTER-Net observations report
  36. EP261006a / AT 2026aetp: Luminance-band optical follow-up with small-aperture telescopes
  37. EP261006a / AT 2026aetp: Multiband optical follow-up with the PKU 60cm Telescope
  38. EP261010a: Global MASTER-Net observations report
  39. EP261003a: J-band upper limit with WINTER
  40. IceCube-260930A: Upper limits from a search for additional neutrino events in IceCube
  41. IceCube Alert 260930A: Global MASTER-Net observations report
  42. EP260927a: Global MASTER-Net observations report
  43. EP260924a: Global MASTER-Net observations report
  44. Fermi GRB 260926C: Global MASTER-Net observations report
  45. GRB 260921A: NuSTAR detection of prompt emission
  46. GRB 260921A: SVOM/GRM observation
  47. GRB 260922A: COLIBRÍ Confirmation of the Optical Counterpart
  48. Konus-Wind detection of GRB 260921A (possible merger-origin)
  49. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  50. GRB 260921A: AstroSat CZTI detection
  51. GRB 260921A: Fermi GBM Observation
  52. GRB 260921A: Swift detection of a burst
  53. GRB 260921A: Fermi GBM Final Real-time Localization
  54. EP260920b: COLIBRÍ optical observations
  55. EP Alert 260921.01: Global MASTER-Net observations report
  56. The EP-WXT trigger 01709318491 is likely a flaring star
  57. IPN triangulation of GRB 260810A
  58. EP Alert 260917.32: Global MASTER-Net observations report
  59. Fermi trigger No 811264269: Global MASTER-Net observations report
  60. EP Alert 260914.53: Global MASTER-Net observations report
  61. GRB 260914A: SVOM/C-GFT optical observations
  62. GRB 260914A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  63. SVOM GRB260914.47: Global MASTER-Net observations report
  64. Fermi trigger No 810554827: Global MASTER-Net observations report
  65. The EP-WXT trigger 01709302592 is likely a flaring star
  66. NuSTAR Transient 260828: SOAR Optical Upper Limits
  67. GRB 260829A: AstroSat CZTI detection
  68. EP260830a: Global MASTER-Net observations report
  69. GRB 260829A: Fermi GBM Detection
  70. GRB 260829A: BALROG localization (Fermi Trigger 809676494 / GRB 260829256)
  71. GRB 260829A: Fermi GBM Final Real-time Localization
  72. Fermi GBM trigger 809666623/260829141 is not a GRB
  73. MAXI GRB260827.40: Global MASTER-Net observations report
  74. IceCube Alert 260825A: Global MASTER-Net observations report
  75. GRB 260818B: VLA radio observations
  76. GRB 260818B: SVOM/GRM observation
  77. EP260812a: AZT-22 optical upper limit
  78. GRB260809A/EPF_J234751.2+210212: EP-FXT follow-up observation
  79. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) optical observation
  80. GRB 260809A: NOT optical observations
  81. EP260809a: J-band upper limit with WINTER
  82. GRB 260808B: LCO optical observations
  83. Fermi GRB 260808A: Global MASTER-Net observations report
  84. SN 2026stf / GRB 260708A: ATLAS forced photometry
  85. Fermi GRB 260802B: Global MASTER-Net observations report
  86. GRB 260802A / EP J223759.5+531421: SVOM/VT optical upper limit
  87. EP 260729a: Ondrejov D50 optical detection supports stellar flare origin
  88. EP260723a: SVOM/VT optical observation
  89. Fermi GRB 260718A: Global MASTER-Net observations report
  90. GRB 260310A / AT2026fgk: Late-time Chandra Detection
  91. EP260711a: EP-FXT follow-up observation
  92. GRB 260629A: AstroSat CZTI detection
  93. GRB 260703A: Fermi GBM Final Localization
  94. Fermi trigger No 804552016: Global MASTER-Net observations report
  95. GRB 260629A: Fermi GBM Final Real-time Localization
  96. Fermi GRB 260628A: Global MASTER-Net observations report
  97. EP260623a: TNG NIR afterglow detection
  98. EP260623a: WINTER J-band observations
  99. GRB 260619A: SVOM possible detection of a faint burst
  100. GRB 260506B: cubesat Avion detection

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