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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"

28112 results found.

  1. GRB 251211B: AstroSat CZTI detection
  2. GRB 251209A: NuSTAR detection of prompt emission
  3. EP251212a : COLIBRÍ optical upper limit
  4. EP251212a: Einstein Probe detection of an X-ray transient
  5. Fermi-LAT Gamma-ray Observations of IceCube-251210A
  6. IceCube-251210A: Upper limits from a search for additional neutrino events in IceCube
  7. Fermi GRB 251211B: Global MASTER-Net observations report
  8. IceCube-251210A: DDOTI Optical Upper Limit
  9. SVOM GRB251211.12: Global MASTER-Net observations report
  10. GRB 251209A: Fermi GBM observation
  11. GRB 251205A: 1.3m DFOT optical upper limit
  12. GRB 251209A: AstroSat CZTI detection
  13. IceCube Alert 251210.46: Global MASTER-Net observations report
  14. EP251124a: Mondy optical upper limit
  15. GRB 251129A/EP251129a: AbAO and Mondy optical observations
  16. EP251130a: Mondy and AbAO optical observations
  17. GRB 251208A: AstroSat CZTI detection
  18. Fermi GBM Sub-Threshold Detection of GRB 251205A
  19. GRB 251208A: Glowbug gamma-ray detection
  20. GRB 251208B: COLIBRÍ optical upper limits
  21. EP251118a / GRB 251118C: VLT/MUSE redshift confirmation
  22. Fermi GRB 251209A: Global MASTER-Net observations report
  23. Fermi GRB 251208C: Global MASTER-Net observations report
  24. GRB 251206A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  25. GRB 251208B: Swift-XRT afterglow detection
  26. GRB 251208D: LAST optical upper limit
  27. GRB 251208D: LCO analysis of the XRT sources
  28. GRB 251208B: Fermi GBM Observation
  29. GRB 251208B: GROWTH-India Telescope optical upper limits
  30. GRB 251205A: J-band detection with WINTER
  31. GRB 251208D: Swift-XRT observations
  32. GRB 251208A: SVOM/GRM observation of a short burst
  33. GRB 251208C: SVOM/GRM observation of a short burst
  34. GRB 251129A: e-MERLIN C-band observations
  35. LAT GRB251208.43: Global MASTER-Net observations report
  36. GRB 251205A: Liverpool Telescope further optical follow-up observations
  37. GRB 251208D: LCO optical upper limits
  38. SVOM GRB251208D: Global MASTER-Net observations report
  39. GRB 251208B: Fermi-LAT detection
  40. GRB 251208B: Swift/BAT-GUANO arcminute localization of a burst
  41. GRB 251208D: SVOM possible detection of a faint burst
  42. GRB 251205A : MITSuME Akeno optical afterglow candidate detection
  43. GRB 251205A: Liverpool Telescope further optical follow-up observations
  44. SVOM GRB251206.86: Global MASTER-Net observations report
  45. GRB 251205A: GROWTH-India Telescope optical observations
  46. GRB 251205A: Swift-BAT refined analysis
  47. GRB 251205A: Swift-XRT refined Analysis
  48. GRB 251205A: Swift/UVOT Detection
  49. GRB 251205A: Liverpool Telescope optical follow-up observations
  50. GRB 251203C: Swift/UVOT Upper Limit
  51. GRB 251205A: COLIBRÍ optical observations
  52. GRB 251205A: NOT optical observations
  53. GRB 251205A: Enhanced Swift-XRT position
  54. Swift GRB 251205A : MASTER OT detection with host galaxy
  55. GRB 251205A: Swift detection of a burst with an optical afterglow
  56. Swift GRB251205A: Global MASTER-Net observations report
  57. SVOM/sb25120502: SVOM detection of a faint X-ray transient candidate
  58. GRB 251202A / EP251202a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm and 1-m telescopes at McDonald Observatory
  59. GRB 251203C: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  60. GRB 251202A: SVOM/GRM observation
  61. GRB 251203A: GECAM-B observation of a burst
  62. GRB 251203A: SVOM/GRM observation
  63. GRB 251203C: J-band observations with WINTER
  64. GRB 251129B: Glowbug gamma-ray detection of a short burst
  65. GRB 251203A: AstroSat CZTI detection
  66. GRB 251203C: SVOM/VT optical counterpart
  67. GRB 251203C: EP-FXT follow-up observation
  68. GRB 251203B: Swift-XRT observations
  69. GRB 251203C: LCO optical upper limits
  70. GRB 251203B: LCO optical upper limits
  71. GRB 251203B: SVOM/VT optical observation
  72. GRB 251202A / EP251202a: Liverpool Telescope optical follow-up observations
  73. SVOM GRB251203.77: Global MASTER-Net observations report
  74. SVOM GRB251203B: Global MASTER-Net observations report
  75. GRB 251203B: SVOM detection of a burst
  76. EP251130a: MAO/AZT-22 optical observations
  77. GRB 251201B: Fermi GBM Observation
  78. EP251202a/GRB 251202A: KAIT optical observations
  79. EP251130a: ULL-ASTRO-MASTER late detection of the optical afterglow with LCO 1-m telescope at Teide Observatory
  80. Fermi GRB 251202B: Global MASTER-Net observations report
  81. IPN triangulation of GRB 251129B (short/hard)
  82. GRB251129A/EP251129a: Swift UVOT detection
  83. GRB 251202A: Fermi GBM Observation
  84. GRB 251202A: Swift/UVOT Detection
  85. GRB 251201B: Kilonova-Catcher optical afterglow detection
  86. GRB 251201B: Swift/UVOT Detection
  87. GRB 251130B: Glowbug gamma-ray detection
  88. EP251130a: continued NOT optical observations indicate steep fading phase
  89. Fermi-LAT Gamma-ray Observations of IceCube-251130A
  90. EP251202a/GRB 251202A: refined analysis of the EP-WXT observations
  91. GRB 251126A: SAO RAS optical marginal detection
  92. GRB 251202A: Swift-XRT afterglow detection
  93. EP251129a/GRB 251129A: NOWT Detection
  94. GRB 251126A: SVOM/VT optical observation
  95. EP251130a: SVOM/VT optical observation
  96. Fermi GRB 251202A: Global MASTER-Net observations report
  97. EP251202a/GRB 251202A: Einstein Probe detection of an X-ray transient
  98. GRB 251201B: Swift-XRT refined Analysis
  99. IceCube-251130A: Upper limits from a search for additional neutrino events in IceCube
  100. GRB 251201A: SVOM/GRM observation of a burst

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