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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"

36314 results found.

  1. GRB 260127B: AstroSat CZTI detection
  2. GRB 260130A: Fermi GBM Detection
  3. GRB 260127B: Fermi GBM Detection
  4. EP260128a / GRB 260128A: COLIBRÍ optical upper limit
  5. Fermi GRB 260130A: Global MASTER-Net observations report
  6. EP260128a / GRB 260128A: NOT and TNG optical and NIR upper limits
  7. GRB 260130A: Fermi GBM Final Real-time Localization
  8. Fermi GRB 260129A: Global MASTER-Net observations report
  9. GRB 260128B: LCO optical upper limits
  10. GRB 260128B: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  11. IPN triangulation of GRB 260121A
  12. GRB 260127A: Swift-BAT refined analysis
  13. GRB 260129B: Fermi GBM Final Localization
  14. GRB 260128B: SVOM detection of a burst through offline search
  15. GRB 260129A: Fermi GBM Final Localization
  16. IPN triangulation of GRB 260127B (short)
  17. GRB 260127B: Swift-XRT observations
  18. GRB 260127A: INASAN-Kislovodsk, SAO RAS, and Terskol K-800 optical observations
  19. GRB 260128A / EP260128a: Fermi-GBM Sub-Threshold Detection
  20. Fermi GRB 260127A: Global MASTER-Net observations report
  21. GRB 260127A: Fermi GBM Observation
  22. IceCube-260125A: Upper limits from a search for additional neutrino events in IceCube
  23. GRB 260127A: COLIBRÍ optical observations
  24. GRB 260127A: NOT optical observations
  25. GRB 260127B: Swift ToO observations
  26. GRB 260127A : MITSuME Akeno optical afterglow candidate detection
  27. GRB 260127A: Swift-XRT refined Analysis
  28. GRB 260127B: GOTO candidate optical counterpart
  29. GRB 260127A: SVOM/C-GFT optical observations
  30. GRB 260127A: Enhanced Swift-XRT position
  31. Fermi GRB 260127B: Global MASTER-Net observations report
  32. GRB 260127B: Fermi GBM Final Real-time Localization
  33. GRB 260127A: Prompt enhanced Swift-XRT position
  34. Swift GRB 260127A: Global MASTER-Net observations report
  35. GRB 260127A: LCO optical afterglow discovery
  36. GRB 260127A: Swift detection of a burst
  37. GRB 260127A: Fermi GBM Final Real-time Localization
  38. GRB 260125A: Swift-XRT observations
  39. GRB 260125A: NOT optical observations on GOTO26acv / AT 2026bjf
  40. Konus-Wind detection of GRB 260120B
  41. GRB 251222A: SVOM/ECLAIRs refined analysis
  42. GRB 260125A: Swift ToO observations
  43. GRB 260125A: GOTO candidate optical counterpart
  44. Fermi GRB 260125B: Global MASTER-Net observations report
  45. GRB 260125B: Fermi GBM Final Real-time Localization
  46. GRB 260125A: Fermi GBM Final Real-time Localization
  47. GRB 260114A: SVOM/VT optical upper limits
  48. GRB 260120A: AstroSat CZTI detection
  49. GRB 260122B: Swift-BAT refined analysis
  50. GRB 260120B: SVOM/GRM observation
  51. GRB 260120A: GECAM-B observation
  52. GRB 260120B: AstroSat CZTI detection
  53. GRB 260114A: Insight-HXMT/HE detection
  54. GRB 260122B: Swift detection of a burst
  55. EP260119a: Assy AZT-20 optical observations
  56. EP260119a: Mondy and SAO RAS optical upper limits
  57. GRB 260122A: Fermi GBM Final Real-time Localization
  58. Fermi GRB 260120C: Global MASTER-Net observations report
  59. GRB 260120B: Swift-BAT refined analysis
  60. GRB 260120B: Swift-XRT refined Analysis
  61. GRB 251122A / EP251122a: VLT/X-shooter host redshift z = 1.765
  62. GRB 260120B: Fermi GBM Observation
  63. GRB 260120B: Swift/UVOT Detection
  64. GRB 260120B: COLIBRÍ optical upper limits
  65. GRB 260120B: Enhanced Swift-XRT position
  66. GRB 260120B: SVOM/C-GFT optical counterpart detection
  67. GRB 260120C: Fermi GBM Final Real-time Localization
  68. GRB 260101A: 239Alferov CubeSat detection
  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. GRB 251202A: further radio observations with the VLA
  74. Trigger 1442421: Swift detection of HMXB 1A 1118-61
  75. EP260119a: KAIT optical observations
  76. GRB 260120A: Fermi GBM Final Real-time Localization
  77. EP260119a: SAO RAS optical observations
  78. GRB 251208D: SVOM/ECLAIRs refined analysis
  79. GRB 251208D: SVOM/ECLAIRs refined analysis
  80. GRB 260117A: Swift-XRT afterglow detection
  81. GRB 260115A: AstroSat CZTI detection
  82. GRB 260117A: ZTSh optical upper limit
  83. GRB 260110A: SVOM detection of a burst through offline search
  84. GRB 260117A: SVOM/COLIBRÍ (FM-GFT) optical observations
  85. GRB 260117A: SVOM/VT optical candidate
  86. GRB 260117A: SVOM/C-GFT upper limit
  87. GRB 260117A: Swift-XRT observations
  88. GRB 260117A: Swift ToO observations
  89. GRB 260117A: SVOM detection of a long faint burst
  90. GRB 260115A: GECAM-B observation
  91. GRB 260114A: VLT/MUSE spectroscopic observations
  92. IceCube-260115A: Upper limits from a search for additional neutrino events in IceCube
  93. GRB 260111A: COLIBRÍ fading of the optical counterpart candidate
  94. GRB 260114A: VLT/HAWK-I further near-infrared upper limits
  95. IceCube-260115A - IceCube observation of a high-energy neutrino candidate track-like event
  96. GRB 260115A: BALROG localization (Fermi Trigger 790192010 / GRB 260115741)
  97. Fermi GRB 260115A: Global MASTER-Net observations report
  98. GRB 260115A: Fermi GBM Final Real-time Localization
  99. GRB 251222A: radio detection with the VLA
  100. GRB 260114A: VLT/HAWK-I near-infrared upper limits

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