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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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').
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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"

39197 results found.

  1. GRB 251025B: SVOM/C-GFT optical counterpart detection
  2. GRB 251025B: SVOM detection of a burst
  3. IceCube-251025A - IceCube observation of a high-energy neutrino candidate track-like event
  4. GRB 251025A (sb25102501): Likely a stellar flare by SVOM/VT
  5. GRB 251025A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  6. GRB 251025A: SVOM/VT VHF optical upper limit
  7. GRB 251025A: SVOM detection of a faint burst
  8. GRB 251003A: VLA Detection
  9. GRB 251024A: Enhanced Swift-XRT position
  10. GRB 251023C: Glowbug gamma-ray detection
  11. GRB 251024A: LCOGT Optical Afterglow Detection
  12. GRB 251022A: KAIT optical observations
  13. GRB 251024A: Swift detection of a burst
  14. Swift GRB 251024A: Global MASTER-Net observations report
  15. GRB 251023B / EP251023b: COLIBRÍ Confirmation of the Fading Nature of the Optical Candidate
  16. GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
  17. GRB 251023B: OHP/T193 optical observations
  18. EP251023a: OHP/T193 optical observations
  19. GRB 251023C: AstroSat CZTI detection
  20. EP251023b/GRB 251023B: JinShan optical observation
  21. GRB 251022A: Swift-XRT detection of GOTO25iym
  22. EP251023b: Global MASTER-Net observations report
  23. EP251023b/GRB 251023B : Einstein Probe detection of a fast X-ray transient
  24. GRB 251023C: CALET Gamma-Ray Burst Monitor detection
  25. GRB 251022A: GROWTH-India Telescope optical observations
  26. GRB 251023C: Swift/BAT-GUANO localization skymap of a burst
  27. EP251023a: GROWTH-India Telescope optical observations
  28. GRB 251022A: Fermi GBM Observation
  29. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  30. GRB 251023A: Glowbug gamma-ray detection
  31. GRB 251023B: Glowbug gamma-ray detection
  32. EP251023a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm telescope at Teide Observatory
  33. EP251023a: Global MASTER-Net observations report
  34. GRB 251023B / EP#01709247298: COLIBRÍ optical counterpart candidate
  35. IPN triangulation of GRB 251016B
  36. GRB 251023B: CALET Gamma-Ray Burst Monitor detection
  37. EP#01709247298: Swift-XRT counterpart detection
  38. EP251023a: COLIBRÍ optical observations
  39. GRB 251013C: further SAO RAS optical observations
  40. GRB 251022A: COLIBRÍ optical observations
  41. GRB 251013C: ISON-Castelgrande observatory optical observations
  42. GRB 251022A: MASTER OT detection
  43. GRB 251022A: DDOTI Optical Detection
  44. EP251021b/GRB 251021A: SVOM/VT optical candidate
  45. GRB 251023B / MAXI J0451+122: MAXI/GSC detection
  46. Fermi GRB 251023A: Global MASTER-Net observations report
  47. GRB 251022A: GOTO optical counterpart detection
  48. GRB 251023A: Fermi GBM Final Localization Correction
  49. GRB 251022A: Fermi-LAT detection
  50. GRB 251016B: Fermi GBM Detection
  51. GRB 251022A: Tiled Swift observations
  52. LAT GRB251022A: Global MASTER-Net observations report
  53. GRB 251022A: Fermi GBM Final Real-time Localization
  54. GRB 251021A/EP251021b: Fermi-GBM Sub-Threshold Detection
  55. GRB 250911A: MAXI/GSC detection
  56. GRB 251016A: SVOM/ECLAIRs refined analysis
  57. Fermi-LAT gamma-ray observations of IceCube-251018A
  58. GRB 251017A : RAPAS follow-up observations
  59. GRB 251017A: COLIBRÍ optical observations of a late plateau
  60. GRB 251017A: Swift-BAT refined analysis
  61. GRB 251016A: Fermi GBM Observation
  62. GRB 251018A: Fermi GBM Observation
  63. GRB 251018A: BOOTES-5 and BOOTES-7 early optical detections
  64. GRB 251018A: Swift-XRT refined Analysis
  65. GRB 251018A: Enhanced Swift-XRT position
  66. Fermi trigger No 782500909: Global MASTER-Net observations report
  67. GRB 251016A: HXMT/HE detection
  68. IceCube-251018A: Global MASTER-Net observations report
  69. GRB 251016A: Swift-XRT afterglow detection
  70. GRB 251017A: Swift/UVOT Detection
  71. GRB 251016A: Swift/UVOT Detection
  72. GRB 251018A: Swift/UVOT Detection
  73. IceCube-251018A - IceCube observation of a high-energy neutrino candidate track-like event
  74. GRB 251017A: VLT/MUSE spectroscopic redshift z = 4.327
  75. GRB 251016A: VLT/FORS2 Optical Observation
  76. GRB 251017A: COLIBRÍ photometric redshift
  77. GRB 251017A: Swift-XRT refined Analysis
  78. GRB 251018A: MASTER OT detection
  79. GRB 251018A: TRT optical afterglow detection
  80. Swift GRB 251018A: Global MASTER-Net observations report
  81. GRB 251018A: Swift detection of a burst with an optical counterpart
  82. GRB 251018A: Fermi GBM Final Real-time Localization
  83. GRB 251017A: SVOM/VT optical observation
  84. GRB 251011A: Fermi GBM Observation
  85. GRB 251017A: OHP/T193 i-band observations
  86. GRB 251013C: OHP/T193 third epoch optical observations and detected rebrightening
  87. GRB 251017A: J-band detection with WINTER
  88. GRB 251017A: Glowbug gamma-ray detection
  89. GRB 251013C: Liverpool Telescope observations
  90. GRB 251013C: Leavitt Observatory optical photometry
  91. Fermi GRB 251016B: Global MASTER-Net observations report
  92. GRB 251017A: JinShan observations of the optical afterglow
  93. Swift GRB 251017A: Global MASTER-Net observations report
  94. GRB 251017A : MITSuME Akeno optical afterglow candidate detection
  95. Swift Trigger 1404295 is not a GRB
  96. GRB 251016A: AstroSat CZTI detection of a short burst
  97. GRB 251017A: Enhanced Swift-XRT position
  98. GRB 251017A: COLIBRÍ Early Afterglow Detection
  99. GRB 251016B: AstroSat CZTI detection
  100. GRB 251017A: BOOTES-5/JGT early optical afterglow detection

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