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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

28086 results found.

  1. GRB 260509A: SAO RAS optical observations
  2. GRB 260511A: REM near-infrared detection
  3. GRB 260511B: GROWTH-India Telescope optical observations
  4. GRB 260506B: Glowbug gamma-ray detection
  5. GRB 260506A: Glowbug gamma-ray detection of a short burst
  6. GRB 260511B: J-band observations by the SYSU 80 cm infrared telescope
  7. GRB 260511B: NuSTAR detection of prompt emission
  8. GRB 260511A: NuSTAR detection of prompt emission
  9. GRB 260511B: Fermi GBM Detection
  10. GRB 260511B: SVOM/VT optical observation with VHF data
  11. GRB 260511B: TRT optical observation
  12. GRB 260511B : MITSuME Akeno optical afterglow candidate detection
  13. GRB 260511A: Fermi GBM Detection
  14. GRB 260511B SVOM/C-GFT optical counterpart detection
  15. EP260509a: LCO optical upper limits
  16. GRB 260511A: UTGO H50 optical afterglow observation
  17. GRB 260511B: SVOM detection of a burst
  18. GRB 260510C: EP-FXT follow-up observation
  19. EP260509a: EP-FXT non-detection and upper limit
  20. GRB 260511A: SVOM/VT optical observation with VHF data
  21. Fermi GRB 260511A: Global MASTER-Net observations report
  22. GRB 260511A: KAIT optical afterglow observations
  23. GRB 260511A: LCO optical afterglow detection
  24. GRB 260511A: SVOM/COLIBRÍ (FM-GFT) optical counterpart
  25. GRB 260511A: TRT optical counterpart detection
  26. GRB 260511A: SVOM detection of a bright burst
  27. GRB 260511A: BALROG localization (Fermi Trigger 800172815 / GRB 260511259)
  28. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  29. GRB 260510C: MAXI/GSC detection
  30. EP260509a: Global MASTER-Net observations report
  31. Fermi GBM Sub-Threshold Detection of GRB 260510B
  32. GRB 260510C: SVOM detection of a burst
  33. GRB 260510B: LCO optical upper limits
  34. EP260509a: Einstein Probe detection of an X-ray transient
  35. GRB 260509A: Liverpool Telescope optical observations
  36. GRB 260510B: SVOM detection of a burst
  37. GRB 260509A: LCO optical observations
  38. SVOM GRB 260509A: MASTER-OAFA optical observation
  39. Fermi GRB 260510A: Global MASTER-Net observations report
  40. GRB 260509A: KAIT optical observations
  41. GRB 260509A: SVOM/COLIBRÍ (FM-GFT) observations
  42. GRB 260509A: SVOM/VT optical candidate with VHF data
  43. GRB 260509A: LCO optical counterpart detection
  44. GRB 260509A: SVOM detection of a burst
  45. IceCube-260504A: Upper limits from a search for additional neutrino events in IceCube
  46. EP260507a: REM optical/NIR observations
  47. EP260507a: refined analysis of the EP-WXT and EP-FXT observations
  48. GRB 260507B / EP260507a: Fermi-GBM Sub-Threshold Detection
  49. EP260507a: COLIBRÍ optical observations
  50. EP260507a: NOT optical observations
  51. EP260507a: further Liverpool Telescope observations
  52. EP260507a: Liverpool Telescope optical upper limits
  53. EP260507a: TRT optical counterpart detection
  54. EP260507a: Kinder optical counterpart candidate
  55. EP260507a: LCO optical counterpart
  56. EP260507a: Einstein Probe detection of an X-ray transient
  57. GRB 260506B: BALROG localization (Fermi Trigger 799765648 / GRB 260506547)
  58. Fermi GRB 260506A: Global MASTER-Net observations report
  59. IceCube Alert 260505A: Global MASTER-Net observations report
  60. GRB 260430B: Glowbug gamma-ray detection
  61. GRB 260421B: radio observation with the VLA
  62. Fermi-LAT Gamma-ray Observations of IceCube-260504A
  63. GRB 260430B: AstroSat CZTI detection of a long burst
  64. GRB 260502A: SVOM/GRM observation of a short GRB
  65. GRB 260503A: SVOM/GRM observation of a GRB
  66. Konus-Wind detection of GRB 260411C
  67. GRB 260504B: REM optical/NIR observations
  68. GRB 260504B: LCO z-band upper limit
  69. SVOM GRB 260504B: MASTER-OAFA optical observations
  70. GRB 260504B: SVOM detection of a short burst
  71. Fermi GRB 260504A: Global MASTER-Net observations report
  72. SVOM/GRM observation of a bright burst from SGR 1E1841-045
  73. GRB 260429B / EP260429a: EP-FXT follow-up observation
  74. EP260502a: Einstein Probe detection of an X-ray transient
  75. GRB 260429A: SVOM/GRM observation of a short burst
  76. SN 2026kid: Optical follow-up with small-aperture telescopes in Spain and China
  77. EP260429a: Global MASTER-Net observations report
  78. EP260430a: refined analysis of the EP-WXT and follow-up EP-FXT observations
  79. GRB 260424B: AstroSat CZTI detection
  80. GRB 260429B / EP260429a: COLIBRÍ optical upper limit
  81. EP260429a: LCO optical upper limits
  82. EP260430a: LCO optical upper limits
  83. GRB 260430A / EP260430a: COLIBRÍ optical upper limit
  84. GRB 260429A: Fermi GBM Detection
  85. Fermi GRB 260429A: Global MASTER-Net observations report
  86. EP260430a: Global MASTER-Net observations report
  87. EP260430a: Einstein Probe detection of an X-ray transient
  88. EP260429a: EP-WXT detection of a fast X-ray transient
  89. GRB 260428A: SVOM/GRM observation of a possible short burst with extended emission
  90. IceCube-260425A: Upper limits from a search for additional neutrino events in IceCube
  91. Fermi GRB 260428A: Global MASTER-Net observations report
  92. EP260416a: Mondy and Terskol optical upper limits
  93. GRB 260424B: Glowbug gamma-ray detection of a short burst
  94. GRB 260424B: COLIBRÍ optical upper limit
  95. Fermi-LAT Gamma-ray Observations of IceCube-260425A
  96. GRB 260305A: likely detection by Fermi-LAT and the LAT gamma-ray position
  97. IceCube Alert 260425A: Global MASTER-Net observations report
  98. Fermi trigger No 798737427: Global MASTER-Net observations report
  99. GRB 260401A: cubesat Avion detection
  100. EP260321a: Upper limits from ATCA radio observations

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