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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').
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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"

45509 results found.

  1. GRB 250506A: GRBAlpha detection
  2. GRB 250512B: SVOM detection of a burst
  3. GRB 250507B: SVOM/GRM observation of a burst
  4. EP250512a: Einstein Probe detection of an X-ray transient
  5. GRB 250512A: Fermi GBM Final Real-time Localization
  6. EP250511a: REM optical/NIR observations
  7. EP250511a: Einstein Probe follow-up obsevation and refined analysis
  8. EP250511a: SVOM/VT optical candidate comfirmation
  9. EP250511a: Global MASTER-Net observations report
  10. EP250511a: COLIBRÍ optical counterpart candidate
  11. EP250511a: BOOTES-5 optical upper limit
  12. EP250511a: Einstein Probe detection of an X-ray transient
  13. EP250508a: Gemini NIR upper limits
  14. GRB 250510B: Fermi GBM Observation
  15. Fermi GRB 250510C: Global MASTER-Net observations report
  16. Fermi GRB 250510B: Global MASTER-Net observations report
  17. GRB 250510C: Fermi GBM Final Real-time Localization
  18. GRB 250510A: Swift-XRT observations
  19. GRB 250509A: Fermi GBM Observation
  20. IceCube-250506A: No Transient Candidates from the Zwicky Transient Facility
  21. GRB 250510A: follow-up observation with EP-FXT
  22. GRB 250510B: Swift/BAT-GUANO localization skymap of a burst
  23. GRB 250510B: Fermi GBM Final Localization
  24. GRB 250510A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  25. GRB 250509A: Swift-XRT refined Analysis
  26. GRB 250510A: SVOM possible detection of a burst
  27. GRB 250507A: J-band observations with WINTER (duplicate submission)
  28. GRB 250507A: J-band observations with WINTER
  29. EP250508a: SVOM/VT optical candidate fading
  30. GRB 250509A: Enhanced Swift-XRT position
  31. GRB 250509A: Prompt enhanced Swift-XRT position
  32. Fermi GRB 250509A: Global MASTER-Net observations report
  33. Swift GRB 250509A: Global MASTER-Net observations report
  34. GRB 250509A: Swift detection of a burst
  35. GRB 250509A: Fermi GBM Final Real-time Localization
  36. GRB 250506A: NOT optical upper limits
  37. EP250508a: Liverpool Telescope optical upper limits
  38. EP250508a: follow-up observation with EP-FXT
  39. EP250508a: SVOM/VT optical candidate
  40. EP250508a: KAIT optical upper limit
  41. GRB 250507A: KAIT optical upper limit
  42. EP250508a: refined analysis of the EP-WXT and EP-FXT observations
  43. GRB 250505B: SVOM/GRM observation of a short burst
  44. GRB 250502A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  45. GRB 250506A: GECAM detection
  46. EP250508a: REM optical/NIR observations
  47. GRB 250506A: Swift-XRT afterglow detection
  48. EP250508a: Global MASTER-Net observations report
  49. GRB 250506A: SVOM/VT optical upper limit
  50. EP250508a: COLIBRÍ Optical Limit
  51. EP250508a: Einstein Probe detection of an X-ray transient
  52. GRB 250507A: Swift-XRT refined Analysis
  53. IceCube-250506A: Upper limits from a search for additional neutrino events in IceCube
  54. GRB 250506A: Swift/UVOT Upper Limits
  55. GRB 250427B : SVOM detection of a burst through offline search
  56. GRB 250507A: follow-up observation with EP-FXT
  57. GRB 250430A / EP250430a: AstroSat CZTI detection
  58. EP#01709175213/IGR J19566+0326: Swift-XRT detection
  59. GRB 250506A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  60. GRB 250507A: refined SVOM/MXT data analysis
  61. GRB 250507A: REM optical/NIR observations
  62. GRB 250507A: SVOM/VT optical upper limit
  63. GRB 250506A: Swift-XRT observations
  64. Fermi-LAT Gamma-ray Observations of IceCube-250506A
  65. GRB 250507A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  66. EP-WXT trigger 01709175213: a new X-ray outburst of LMXB MAXI J1957+032
  67. GRB 250507A: SVOM detection of a long burst
  68. GRB 250506A: Mephisto optical upper limits
  69. GRB 250504A: EIRSAT-1 GMOD Detection
  70. GRB 250506A: Swift ToO observations
  71. GRB 250502A: Bassano Bresciano Observatory upper limit
  72. IceCube-250506A - IceCube observation of a high-energy neutrino candidate track-like event
  73. IceCube Alert 250506.59: Global MASTER-Net observations report
  74. GRB 250430A: Konus-Wind detection and joint Konus-Wind+Swift-BAT spectral analysis
  75. GRB 250506A: Xinglong 2.16m optical upper limit
  76. SVOM/sb25050601: EP-FXT observations
  77. GRB 250506A: SVOM improved position and MXT detection of a fading X-ray afterglow
  78. GRB 250506A: REM optical/NIR upper limits
  79. GRB 250506A: Fermi GBM Observation
  80. GRB 250506A: Swift XRT observations and possible counterpart detection
  81. GRB 250506A: TRT optical observations
  82. GRB 250506A: SVOM/COLIBRÍ (FM-GFT) Upper Limits on the Optical Counterpart
  83. GRB 250506A: SVOM detection of a burst
  84. GRB 250504A: Swift-BAT refined analysis
  85. GRB 250430A: Swift-BAT refined analysis
  86. GRB 250506A: Fermi GBM Final Real-time Localization
  87. GRB 250504A: Swift-XRT refined Analysis
  88. GRB 250504A: VLT/X-shooter upper limits
  89. Fermi GRB 250505A: Global MASTER-Net observations report
  90. GRB 250504A: SVOM/VT upper limit
  91. GRB 250504A: REM optical/NIR observations
  92. GRB 250502A: REM optical/NIR observations
  93. GRB 250505A: Fermi GBM Final Real-time Localization
  94. GRB 250504A: MeerLICHT optical afterglow detection
  95. GRB 250504A: Fermi GBM Observation
  96. GRB 250504A: Enhanced Swift-XRT position
  97. Fermi GRB 250504A: Global MASTER-Net observations report
  98. GRB 250504A: Swift detection of a burst
  99. GRB 250504A: Fermi GBM Final Real-time Localization
  100. Swift GRB250504.98: Global MASTER-Net observations report

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