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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"

27941 results found.

  1. GRB 250522A: Fermi GBM Final Real-time Localization
  2. EP#01709176612: Swift-XRT counterpart detection of flaring star
  3. GRB 250521D: GOTO detects LAST counterpart candidate prior to the GRB
  4. GRB 250521D: LAST tentative optical counterpart candidate
  5. GRB 250520A: CALET Gamma-Ray Burst Monitor detection
  6. GRB 250521B: Swift ToO observations
  7. GRB 250521D: Fermi GBM Final Real-time Localization
  8. GRB 250521C: Fermi GBM Final Localization
  9. GRB 250521B: SVOM detection of a burst through offline search
  10. Konus-Wind detection of GRB 250520A (short/hard)
  11. GRB 250520A: Swift/UVOT Upper Limits
  12. GRB 250521A: Fermi GBM Final Real-time Localization
  13. Konus-Wind detection of GRB 250516B
  14. IPN triangulation of GRB 250516B
  15. GRB 250520A: J-band observations with WINTER
  16. GRB 250520A: Swift-XRT refined Analysis
  17. GRB 250520A: REM optical/NIR early observations
  18. GRB 250520B: Fermi GBM Final Real-time Localization
  19. GRB 250520A:SVOM/VT optical candidate
  20. GRB 250520A: COLIBRÍ optical upper limit
  21. GRB 250520A: DDOTI Optical Upper Limit
  22. GRB 250520A: AstroSat CZTI detection of a short burst
  23. GRB 250516B: GRBAlpha detection
  24. GRB 250520A: SVOM/GRM observation
  25. GRB 250520A: Enhanced Swift-XRT position
  26. GRB 250520A: GOTO optical upper limit
  27. GRB 250520A: Prompt enhanced Swift-XRT position
  28. GRB 250520A: Swift detection of a burst
  29. Swift GRB 250520A: Global MASTER-Net observations report
  30. GRB 250516B: Insight-HXMT detection
  31. EP250427a/GRB250427A: VLA Detection of Radio Counterpart
  32. GRB 250516A: Swift-BAT refined analysis
  33. Konus-Wind detection of GRB 250516A
  34. GRB 250516B: NuSTAR Detection of the Prompt Emission
  35. EP-WXT trigger (ID: 01709176312): a new X-ray outburst of HMXB RX J0111.2-7317
  36. GRB 250515A: Swift-XRT observations
  37. Swift GRB 250516A: Global MASTER-Net observations report
  38. GRB 250515A: 1.6m Mephisto optical detection
  39. GRB 250516A: AstroSat CZTI detection
  40. GRB 250516A: Fermi GBM Observation
  41. GRB 250516A: Swift-XRT refined Analysis
  42. GRB 250516A: Swift/UVOT Detection
  43. GRB 250515A: Swift ToO observations
  44. GRB 250516B: GECAM-B detection of a bright long burst
  45. GRB 250516A: Enhanced Swift-XRT position
  46. GRB 250516A: Swift detection of a burst
  47. GRB 250516A: Fermi GBM Final Real-time Localization
  48. GRB 250515A: Fermi GBM Final Localization
  49. GRB 250424A: COLIBRÍ detection of the associated supernova
  50. Konus-Wind detection of GRB 250512B / EP250512a
  51. GRB 250502A: TESS observations
  52. GRB 250511A: GECAM-A detection of a short burst
  53. GRB 250509A: Swift-BAT refined analysis
  54. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Final Epochs)
  55. Konus-Wind detection of GRB 250506A
  56. GRB 250507B: AstroSat CZTI detection
  57. GRB 250507B: GRBAlpha detection
  58. GRB 250506A: GRBAlpha detection
  59. GRB 250512B: SVOM detection of a burst
  60. EP250512a: Einstein Probe detection of an X-ray transient
  61. GRB 250512A: Fermi GBM Final Real-time Localization
  62. EP250511a: BOOTES-5 optical upper limit
  63. EP250511a: Einstein Probe detection of an X-ray transient
  64. GRB 250510B: Fermi GBM Observation
  65. GRB 250510C: Fermi GBM Final Real-time Localization
  66. GRB 250510A: Swift-XRT observations
  67. GRB 250509A: Fermi GBM Observation
  68. GRB 250510A: follow-up observation with EP-FXT
  69. GRB 250510B: Swift/BAT-GUANO localization skymap of a burst
  70. GRB 250510B: Fermi GBM Final Localization
  71. GRB 250509A: Swift-XRT refined Analysis
  72. GRB 250510A: SVOM possible detection of a burst
  73. GRB 250507A: J-band observations with WINTER
  74. GRB 250509A: Enhanced Swift-XRT position
  75. GRB 250509A: Prompt enhanced Swift-XRT position
  76. Swift GRB 250509A: Global MASTER-Net observations report
  77. GRB 250509A: Swift detection of a burst
  78. GRB 250509A: Fermi GBM Final Real-time Localization
  79. GRB 250506A: NOT optical upper limits
  80. EP250508a: Liverpool Telescope optical upper limits
  81. EP250508a: follow-up observation with EP-FXT
  82. GRB 250506A: GECAM detection
  83. GRB 250506A: Swift-XRT afterglow detection
  84. EP250508a: Einstein Probe detection of an X-ray transient
  85. GRB 250507A: Swift-XRT refined Analysis
  86. GRB 250506A: Swift/UVOT Upper Limits
  87. GRB 250427B : SVOM detection of a burst through offline search
  88. GRB 250430A / EP250430a: AstroSat CZTI detection
  89. EP#01709175213/IGR J19566+0326: Swift-XRT detection
  90. GRB 250506A: Swift-XRT observations
  91. EP-WXT trigger 01709175213: a new X-ray outburst of LMXB MAXI J1957+032
  92. GRB 250507A: SVOM detection of a long burst
  93. GRB 250504A: EIRSAT-1 GMOD Detection
  94. GRB 250506A: Swift ToO observations
  95. IceCube-250506A - IceCube observation of a high-energy neutrino candidate track-like event
  96. GRB 250430A: Konus-Wind detection and joint Konus-Wind+Swift-BAT spectral analysis
  97. GRB 250506A: SVOM improved position and MXT detection of a fading X-ray afterglow
  98. GRB 250506A: Swift XRT observations and possible counterpart detection
  99. GRB 250506A: TRT optical observations
  100. GRB 250506A: SVOM detection of a burst

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