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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"

28100 results found.

  1. EP260507a: Infrared J and Hs upper limits with MDM/MIRAGE
  2. GRB 260511A: Glowbug gamma-ray detection
  3. GRB 260511B: SAO RAS optical observations
  4. GRB 260510D: Glowbug gamma-ray detection of a likely short burst
  5. GRB 260511B: FRAM-ORM optical detection
  6. GRB 260511A: EP-FXT follow-up observation
  7. GRB 260511B: EP-FXT follow-up observation
  8. GRB 260511B: LCO optical counterpart detection
  9. GRB260511B: MAO/AZT-22 optical observations
  10. GRB 260511B: LCO optical observations
  11. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) further optical observations
  12. GRB 260511B: SVOM/COLIBRÍ (FM-GFT) optical observations
  13. GRB 260510B: EP-FXT follow-up observation
  14. GRB 260510C: Fermi GBM Observation
  15. GRB 260509A: SAO RAS optical observations
  16. GRB 260511A: REM near-infrared detection
  17. GRB 260511B: GROWTH-India Telescope optical observations
  18. GRB 260506B: Glowbug gamma-ray detection
  19. GRB 260506A: Glowbug gamma-ray detection of a short burst
  20. GRB 260511B: J-band observations by the SYSU 80 cm infrared telescope
  21. GRB 260511B: NuSTAR detection of prompt emission
  22. GRB 260511A: NuSTAR detection of prompt emission
  23. GRB 260511B: Fermi GBM Detection
  24. GRB 260511B: SVOM/VT optical observation with VHF data
  25. GRB 260511B: TRT optical observation
  26. GRB 260511B : MITSuME Akeno optical afterglow candidate detection
  27. GRB 260511A: Fermi GBM Detection
  28. GRB 260511B SVOM/C-GFT optical counterpart detection
  29. EP260509a: LCO optical upper limits
  30. GRB 260511A: UTGO H50 optical afterglow observation
  31. GRB 260511B: SVOM detection of a burst
  32. GRB 260510C: EP-FXT follow-up observation
  33. EP260509a: EP-FXT non-detection and upper limit
  34. GRB 260511A: SVOM/VT optical observation with VHF data
  35. Fermi GRB 260511A: Global MASTER-Net observations report
  36. GRB 260511A: KAIT optical afterglow observations
  37. GRB 260511A: LCO optical afterglow detection
  38. GRB 260511A: SVOM/COLIBRÍ (FM-GFT) optical counterpart
  39. GRB 260511A: TRT optical counterpart detection
  40. GRB 260511A: SVOM detection of a bright burst
  41. GRB 260511A: BALROG localization (Fermi Trigger 800172815 / GRB 260511259)
  42. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  43. GRB 260510C: MAXI/GSC detection
  44. EP260509a: Global MASTER-Net observations report
  45. Fermi GBM Sub-Threshold Detection of GRB 260510B
  46. GRB 260510C: SVOM detection of a burst
  47. GRB 260510B: LCO optical upper limits
  48. EP260509a: Einstein Probe detection of an X-ray transient
  49. GRB 260509A: Liverpool Telescope optical observations
  50. GRB 260510B: SVOM detection of a burst
  51. GRB 260509A: LCO optical observations
  52. SVOM GRB 260509A: MASTER-OAFA optical observation
  53. Fermi GRB 260510A: Global MASTER-Net observations report
  54. GRB 260509A: KAIT optical observations
  55. GRB 260509A: SVOM/COLIBRÍ (FM-GFT) observations
  56. GRB 260509A: SVOM/VT optical candidate with VHF data
  57. GRB 260509A: LCO optical counterpart detection
  58. GRB 260509A: SVOM detection of a burst
  59. IceCube-260504A: Upper limits from a search for additional neutrino events in IceCube
  60. EP260507a: REM optical/NIR observations
  61. EP260507a: refined analysis of the EP-WXT and EP-FXT observations
  62. GRB 260507B / EP260507a: Fermi-GBM Sub-Threshold Detection
  63. EP260507a: COLIBRÍ optical observations
  64. EP260507a: NOT optical observations
  65. EP260507a: further Liverpool Telescope observations
  66. EP260507a: Liverpool Telescope optical upper limits
  67. EP260507a: TRT optical counterpart detection
  68. EP260507a: Kinder optical counterpart candidate
  69. EP260507a: LCO optical counterpart
  70. EP260507a: Einstein Probe detection of an X-ray transient
  71. GRB 260506B: BALROG localization (Fermi Trigger 799765648 / GRB 260506547)
  72. Fermi GRB 260506A: Global MASTER-Net observations report
  73. IceCube Alert 260505A: Global MASTER-Net observations report
  74. GRB 260430B: Glowbug gamma-ray detection
  75. GRB 260421B: radio observation with the VLA
  76. Fermi-LAT Gamma-ray Observations of IceCube-260504A
  77. GRB 260430B: AstroSat CZTI detection of a long burst
  78. GRB 260502A: SVOM/GRM observation of a short GRB
  79. GRB 260503A: SVOM/GRM observation of a GRB
  80. Konus-Wind detection of GRB 260411C
  81. GRB 260504B: REM optical/NIR observations
  82. GRB 260504B: LCO z-band upper limit
  83. SVOM GRB 260504B: MASTER-OAFA optical observations
  84. GRB 260504B: SVOM detection of a short burst
  85. Fermi GRB 260504A: Global MASTER-Net observations report
  86. SVOM/GRM observation of a bright burst from SGR 1E1841-045
  87. GRB 260429B / EP260429a: EP-FXT follow-up observation
  88. EP260502a: Einstein Probe detection of an X-ray transient
  89. GRB 260429A: SVOM/GRM observation of a short burst
  90. SN 2026kid: Optical follow-up with small-aperture telescopes in Spain and China
  91. EP260429a: Global MASTER-Net observations report
  92. EP260430a: refined analysis of the EP-WXT and follow-up EP-FXT observations
  93. GRB 260424B: AstroSat CZTI detection
  94. GRB 260429B / EP260429a: COLIBRÍ optical upper limit
  95. EP260429a: LCO optical upper limits
  96. EP260430a: LCO optical upper limits
  97. GRB 260430A / EP260430a: COLIBRÍ optical upper limit
  98. GRB 260429A: Fermi GBM Detection
  99. Fermi GRB 260429A: Global MASTER-Net observations report
  100. EP260430a: Global MASTER-Net observations report

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