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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"

32685 results found.

  1. Fermi GRB 260127B: Global MASTER-Net observations report
  2. Swift GRB 260127A: Global MASTER-Net observations report
  3. GRB 260127A: LCO optical afterglow discovery
  4. GRB 260125A: Swift-XRT observations
  5. EP260126a: EP-FXT follow-up observation
  6. EP260126a: Optical upper limit with Kinder observations
  7. EP260126a: Liverpool Telescope optical upper limits
  8. EP260126a: Further NOT optical upper limits
  9. EP260126a: COLIBRÍ optical upper limits
  10. EP260126a: NOT optical observations
  11. Fermi-LAT Gamma-ray Observations of IceCube-260125A
  12. GRB 260125A: NOT optical observations on GOTO26acv / AT 2026bjf
  13. Konus-Wind detection of GRB 260120B
  14. GRB 251222A: SVOM/ECLAIRs refined analysis
  15. GRB 260125A: Swift ToO observations
  16. GRB 260125A: GOTO candidate optical counterpart
  17. Fermi GRB 260125B: Global MASTER-Net observations report
  18. IceCube-260125A - IceCube observation of a high-energy neutrino candidate track-like event
  19. GRB 260114A: SVOM/VT optical upper limits
  20. GRB 260120A: AstroSat CZTI detection
  21. GRB 260122B: Swift-BAT refined analysis
  22. GRB 260120B: SVOM/GRM observation
  23. GRB 260120A: GECAM-B observation
  24. GRB 260120B: AstroSat CZTI detection
  25. GRB 260114A: Insight-HXMT/HE detection
  26. EP260119a: Assy AZT-20 optical observations
  27. EP260119a: Mondy and SAO RAS optical upper limits
  28. IceCube-260115A: No Candidate Transients from the Zwicky Transient Facility
  29. EP260119a: Xinglong optical upper limit
  30. Fermi GRB 260120C: Global MASTER-Net observations report
  31. GRB 260120B: Swift-BAT refined analysis
  32. EP260116a: COLIBRÍ further observations
  33. GRB 251122A / EP251122a: VLT/X-shooter host redshift z = 1.765
  34. GRB 260120B: Fermi GBM Observation
  35. EP260105a: GTC/HiPERCAM optical observations
  36. GRB 260120B: Swift/UVOT Detection
  37. GRB 260120B: COLIBRÍ optical upper limits
  38. GRB 260120B: SVOM/C-GFT optical counterpart detection
  39. GRB 260101A: 239Alferov CubeSat detection
  40. EP260116a: COLIBRÍ observations of a tentative optical rebrightening
  41. EP260119A: Mondy I-Band Observations
  42. GRB 260114A: Swift/UVOT Upper Limits
  43. EP260119a: Liverpool Telescope optical follow-up observations
  44. GRB 251202A: further radio observations with the VLA
  45. Trigger 1442421: Swift detection of HMXB 1A 1118-61
  46. EP260119A: GTC/OSIRIS+ spectroscopic redshift z = 5.47
  47. EP260119a: KAIT optical observations
  48. EP260119a: SVOM/VT optical observation
  49. EP260119a: update of EP-FXT follow-up observation
  50. EP260119a: NOT optical observations
  51. EP260119a: SAO RAS optical observations
  52. EP260116a: COLIBRÍ detection of a fading optical source
  53. GRB 251208D: SVOM/ECLAIRs refined analysis
  54. GRB 251208D: SVOM/ECLAIRs refined analysis
  55. GRB 260117A: Swift-XRT afterglow detection
  56. EP260119a: COLIBRÍ photometric redshift z ≈ 5.6
  57. EP260119a: Global MASTER-Net observations report
  58. GRB 260115A: AstroSat CZTI detection
  59. EP260119a: LCO optical observations
  60. GRB 260117A: ZTSh optical upper limit
  61. EP260119a: COLIBRÍ optical counterpart candidate
  62. EP260119a: preliminary result from the EP-FXT observation
  63. GRB 260117A: SVOM/COLIBRÍ (FM-GFT) optical observations
  64. Fermi-LAT Gamma-ray Observations of IceCube-260115A
  65. Swift trigger on the HMXB 1A 1118-61
  66. GRB 260117A: SVOM/VT optical candidate
  67. GRB 260117A: SVOM/C-GFT upper limit
  68. GRB 260117A: Swift ToO observations
  69. EP 260116a: COLIBRÍ optical upper limit
  70. GRB 260115A: GECAM-B observation
  71. FRB 20251229A: COLIBRÍ further inspection of the updated localization
  72. EP260116a: Liverpool Telescope upper limits
  73. FRB 20251229A: Updated CHIME/FRB Baseband Localization of FRB 20251229A
  74. EP260116A: 1.3m DFOT optical upper limit
  75. GRB 260114A: VLT/MUSE spectroscopic observations
  76. IceCube-260115A: Upper limits from a search for additional neutrino events in IceCube
  77. EP260116a: Global MASTER-Net observations report
  78. GRB 260111A: COLIBRÍ fading of the optical counterpart candidate
  79. EP260116a: Xinglong optical upper limit
  80. GRB 260114A: VLT/HAWK-I further near-infrared upper limits
  81. IceCube-260115A - IceCube observation of a high-energy neutrino candidate track-like event
  82. IceCube: GCN Notices for high-energy track alerts now streamed via Kafka
  83. Fermi GRB 260115A: Global MASTER-Net observations report
  84. GRB260114A: STEP/T80S optical limits
  85. GRB 251222A: radio detection with the VLA
  86. GRB 260114A: VLT/HAWK-I near-infrared upper limits
  87. Konus-Wind detection of GRB 260114A
  88. GRB 260114A: 6 GHz VLA observations
  89. GRB 260114A: VLT/X-shooter redshift of the putative host galaxy
  90. GRB 260114A : MITSuME Akeno optical upper limits
  91. GRB 260114A: COLIBRÍ optical upper limits
  92. GRB 260114A: TNG NIR upper limit
  93. GRB 260114A: NOT optical observations
  94. Konus-Wind detection of GRB 251230A / EP251230a
  95. GRB 260114A: SVOM/GRM observation of a short burst
  96. Swift GRB 260114A: Global MASTER-Net observations report
  97. GRB 260114A: GECAM-B observation of a short burst
  98. GRB 260114A: Mondy optical observations
  99. GRB 260114A: Fermi GBM observation
  100. GRB 260112B: GECAM-B observation

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