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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"

12170 results found.

  1. EP261015a: MAO/AZT-22 optical observations
  2. IceCube-261020A: Upper limits from a search for additional neutrino events in IceCube
  3. NuSTAR 261020, a 830s hard X-ray transient
  4. EP261015a: GSP multiband optical follow-up observations
  5. EP261015a: Further optical observations with the 1.3m DFOT
  6. GRB 261020B: AstroSat CZTI detection of a short burst
  7. Fermi-LAT Gamma-ray Observations of IceCube-261020A
  8. EP261015a: AZT-20 Assy-Turgen optical observations
  9. GRB 261020A: Fermi GBM Observation
  10. EP261015a: Terskol Zeiss-2000 optical upper limit
  11. GRB 261017A: COLIBRÍ optical upper limit
  12. IceCube-261020A - IceCube observation of a high-energy neutrino candidate track-like event
  13. GRB 261020A: MAXI GSC detection
  14. GRB 261020A: Fermi GBM Final Real-time Localization
  15. EP261015a: COLIBRÍ optical observations of a rebrightening
  16. Konus-Wind detection of GRB 261017A
  17. GRB 261017A: J band upper limit by the SYSU 80cm infrared telescope
  18. GRB 261017A: Swift-XRT refined Analysis
  19. EP261015a: Tentative fading of the candidate optical counterpart from the NOT
  20. EP261015b: Refined analysis of EP-FXT observations
  21. EP261015b: J-band upper limit by the SYSU 80cm infrared telescope
  22. EP261015a: refined analysis of EP-FXT observations
  23. EP261015c: J-band upper limit with WINTER
  24. GRB 261010A: VLA radio observations
  25. EP261015a: Einstein Probe detection of a fast X-ray transient
  26. GRB 261010A: LBT tentative near-infrared detection
  27. GRB 261011A: SAO RAS and AbAO optical observations
  28. EP261006a : MeerKAT radio observations.
  29. Fermi-LAT Gamma-ray Observations of IceCube-261012A
  30. GRB 261010A: J-band upper limit by the SYSU 80cm infrared telescope
  31. GRB 261010A: Swift-XRT refined Analysis
  32. GRB 261011A: Swift-XRT refined Analysis
  33. GRB 261010A: 10.4m GTC spectroscopy of the galaxy 2" from the afterglow
  34. Konus-Wind detection of GRB 261010A
  35. Konus-Wind detection of GRB 261011A
  36. Konus-Wind detection of GRB 261007A/EP261007a
  37. GRB 261012A: MAXI GSC detection
  38. GRB 261011A: J-band observations by the SYSU 80cm infrared telescope
  39. GRB 261011A: Optical follow-up observations with Kinder
  40. GRB 261011A: SVOM/VT optical observation from VHF data
  41. EP261010a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  42. EP261006a / AT 2026aetp: Luminance-band optical follow-up with small-aperture telescopes
  43. EP261010a: SVOM/VT optical upper limits
  44. EP261010a Einstein Probe detection of an X-ray transient
  45. EP261007b: J-band upper limit by SYSU 80cm infrared telescope
  46. EP261007b: Refined analysis of the EP-WXT and autonomous EP-FXT observations
  47. EP261006a / AT 2026aetp: VLT/X-shooter spectroscopic redshift z = 0.1853
  48. GRB 261007A: NOT optical observations
  49. EP261007b: NOT optical observations, variable source outside the FXT region
  50. GRB 261007A / EP261007a: AstroSat CZTI detection
  51. EP261007a/GRB 261007A：Xinglong optical observation
  52. GRB 261007A/EP261007a: Optical follow-up observations with Kinder
  53. EP261006a: Optical follow-up observations with Kinder
  54. EP261006a: Liverpool Telescope optical observations
  55. EP261006a: Early Optical Observations by WFST
  56. GRB 261007A: Swift-XRT afterglow detection
  57. EP261007b: Einstein Probe detection of an X-ray transient
  58. GRB 261007A: SVOM/C-GFT optical observations
  59. GRB 261007B: Fermi GBM Final Real-time Localization
  60. EP261007a/GRB 261007A: Einstein Probe detection of an X-ray transient
  61. EP261006a: Einstein Probe detection of an X-ray transient
  62. GRB 261007A: SVOM detection of a burst
  63. GRB 261005B: Swift-XRT refined Analysis
  64. EP trigger 01709320985: Ondrejov D50 optical upper limits
  65. GRB 261005A: Glowbug gamma-ray detection
  66. GRB 261005A: Fermi GBM Final Real-time Localization
  67. GRB 261002A: Fermi GBM Final Localization
  68. EP#01709320865: Swift-XRT observations
  69. Konus-Wind detection of GRB 260919A / EP 260920a
  70. Fermi GRB 261003A: Global MASTER-Net observations report
  71. EP261003a: Einstein Probe detection of an X-ray transient
  72. EP Alert 261003.01: Global MASTER-Net observations report
  73. Fermi-LAT Gamma-ray Observations of IceCube-260930A
  74. Fermi GRB 260930B: Global MASTER-Net observations report
  75. IceCube Alert 260930A: Global MASTER-Net observations report
  76. GRB 260926C: AstroSat CZTI detection
  77. GRB 260926A: GECAM-B observation
  78. EP260927a: Einstein Probe detection of a fast X-ray transient
  79. GRB 260926A: Glowbug gamma-ray detection
  80. GRB 260924A: Swift/UVOT UV grism spectrum results
  81. Fermi GRB 260926C: Global MASTER-Net observations report
  82. Fermi GRB 260926A: Global MASTER-Net observations report
  83. GRB 260926A: Fermi GBM Final Real-time Localization
  84. GRB 260924A: COLIBRÍ optical observations
  85. GRB 260925A: J-band upper limit by SYSU 80cm infrared telescope
  86. GRB 260925A: Swift-XRT refined Analysis
  87. Swift Trigger 1513439 is probably not a GRB
  88. Konus-Wind detection of GRB 260924A
  89. GRB 260924A: Optical follow-up observations with Kinder
  90. GRB 260925A: COLIBRÍ optical upper limits
  91. EP260924a: J-band upper limit with WINTER
  92. GRB 260925A: Swift detection of a burst
  93. GRB 260924A: Swift-XRT refined Analysis
  94. Konus-Wind detection of GRB 260922A
  95. Konus-Wind detection of GRB 260921A (possible merger-origin)
  96. GRB 260924A: Fermi-LAT detection of a bright burst
  97. GRB 260924A: AstroSat CZTI detection
  98. GRB 260924A: Swift detection of a burst
  99. Fermi GRB 260923A: Global MASTER-Net observations report
  100. Fermi-LAT Gamma-ray Observations of IceCube-260919A

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