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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"

38663 results found.

  1. GRB 260128A / EP260128a: Fermi-GBM Sub-Threshold Detection
  2. EP260128a: NOT optical counterpart candidate
  3. EP260128a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  4. EP260128a: Liverpool Telescope optical observations and possible counterpart
  5. EP260128a: LCO optical upper limits
  6. EP260126a: SVOM/VT optical upperlimit
  7. EP260128a: Einstein Probe detection of an X-ray transient
  8. IceCube-260125A: No Candidate Transients from the Zwicky Transient Facility
  9. GRB 260127A: Fermi GBM Observation
  10. IceCube-260125A: Upper limits from a search for additional neutrino events in IceCube
  11. GRB 260127A: COLIBRÍ optical observations
  12. GRB 260127A: NOT optical observations
  13. GRB 260127B: Swift ToO observations
  14. EP260126a: Seimei/TriCCS optical upper limit
  15. GRB 260127A : MITSuME Akeno optical afterglow candidate detection
  16. GRB 260127A: Swift-XRT refined Analysis
  17. GRB 260127B: GOTO candidate optical counterpart
  18. GRB 260127A: SVOM/C-GFT optical observations
  19. The EP-WXT trigger 01709253145 is likely a flaring star
  20. GRB 260127A: Enhanced Swift-XRT position
  21. GRB 260127B: Fermi GBM Final Real-time Localization
  22. GRB 260127A: Prompt enhanced Swift-XRT position
  23. GRB 260127A: LCO optical afterglow discovery
  24. GRB 260127A: Swift detection of a burst
  25. GRB 260127A: Fermi GBM Final Real-time Localization
  26. GRB 260125A: Swift-XRT observations
  27. EP260126a: EP-FXT follow-up observation
  28. EP260126a: Optical upper limit with Kinder observations
  29. EP260126a: Liverpool Telescope optical upper limits
  30. EP260126a: Further NOT optical upper limits
  31. EP260126a: COLIBRÍ optical upper limits
  32. EP260126a: NOT optical observations
  33. EP260126a: Einstein Probe detection of a fast X-ray transient
  34. Fermi-LAT Gamma-ray Observations of IceCube-260125A
  35. GRB 260125A: NOT optical observations on GOTO26acv / AT 2026bjf
  36. Konus-Wind detection of GRB 260120B
  37. GRB 251222A: SVOM/ECLAIRs refined analysis
  38. GRB 260125A: Swift ToO observations
  39. GRB 260125A: GOTO candidate optical counterpart
  40. IceCube-260125A - IceCube observation of a high-energy neutrino candidate track-like event
  41. GRB 260125B: Fermi GBM Final Real-time Localization
  42. GRB 260125A: Fermi GBM Final Real-time Localization
  43. GRB 260114A: SVOM/VT optical upper limits
  44. GRB 260120A: AstroSat CZTI detection
  45. GRB 260120B: SVOM/GRM observation
  46. GRB 260120A: GECAM-B observation
  47. GRB 260120B: AstroSat CZTI detection
  48. GRB 260114A: Insight-HXMT/HE detection
  49. GRB 260122B: Swift detection of a burst
  50. EP260119a: Assy AZT-20 optical observations
  51. EP260119a: Mondy and SAO RAS optical upper limits
  52. GRB 260122A: Fermi GBM Final Real-time Localization
  53. IceCube-260115A: No Candidate Transients from the Zwicky Transient Facility
  54. EP260119a: Xinglong optical upper limit
  55. The EP-WXT trigger 01709251871 is likely a flaring star
  56. GRB 260120B: Swift-XRT refined Analysis
  57. EP260116a: COLIBRÍ further observations
  58. GRB 251122A / EP251122a: VLT/X-shooter host redshift z = 1.765
  59. GRB 260120B: Fermi GBM Observation
  60. EP260105a: GTC/HiPERCAM optical observations
  61. GRB 260120B: Swift/UVOT Detection
  62. GRB 260120B: COLIBRÍ optical upper limits
  63. SVOM GRB260121.06: Global MASTER-Net observations report
  64. GRB 260120B: Enhanced Swift-XRT position
  65. GRB 260120B: SVOM/C-GFT optical counterpart detection
  66. GRB 260120C: Fermi GBM Final Real-time Localization
  67. GRB 260101A: 239Alferov CubeSat detection
  68. EP260116a: COLIBRÍ observations of a tentative optical rebrightening
  69. GRB 260120B: Swift detection of a burst
  70. GRB 260120B: Fermi GBM Final Real-time Localization
  71. EP260119A: Mondy I-Band Observations
  72. GRB 260114A: Swift/UVOT Upper Limits
  73. EP260119a: Liverpool Telescope optical follow-up observations
  74. GRB 251202A: further radio observations with the VLA
  75. Trigger 1442421: Swift detection of HMXB 1A 1118-61
  76. EP260119A: GTC/OSIRIS+ spectroscopic redshift z = 5.47
  77. EP260119a: KAIT optical observations
  78. GRB 260120A: Fermi GBM Final Real-time Localization
  79. EP260119a: SVOM/VT optical observation
  80. EP260119a: update of EP-FXT follow-up observation
  81. EP260119a: NOT optical observations
  82. EP260119a: SAO RAS optical observations
  83. SVOM GRB260119.92: Global MASTER-Net observations report
  84. SVOM GRB260119.92: Global MASTER-Net observations report
  85. SVOM GRB260119.90: Global MASTER-Net observations report
  86. EP260116a: COLIBRÍ detection of a fading optical source
  87. GRB 251208D: SVOM/ECLAIRs refined analysis
  88. GRB 251208D: SVOM/ECLAIRs refined analysis
  89. GRB 260117A: Swift-XRT afterglow detection
  90. EP260119a: COLIBRÍ photometric redshift z ≈ 5.6
  91. GRB 260115A: AstroSat CZTI detection
  92. EP260119a: LCO optical observations
  93. GRB 260117A: ZTSh optical upper limit
  94. EP260119a: COLIBRÍ optical counterpart candidate
  95. EP260119a: preliminary result from the EP-FXT observation
  96. GRB 260110A: SVOM detection of a burst through offline search
  97. EP260119a: EP-WXT detection of a fast X-ray transient
  98. GRB 260117A: SVOM/COLIBRÍ (FM-GFT) optical observations
  99. SVOM GRB260117.82: Global MASTER-Net observations report
  100. Fermi-LAT Gamma-ray Observations of IceCube-260115A

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