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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"

32575 results found.

  1. GRB 250516A: Swift-BAT refined analysis
  2. GRB 250516A: COLIBRÍ optical upper limit
  3. Konus-Wind detection of GRB 250516A
  4. GRB 250516B: NuSTAR Detection of the Prompt Emission
  5. Fermi GRB 250516A: Global MASTER-Net observations report
  6. GRB 250515A: Swift-XRT observations
  7. GRB 250515A: NOT classification of GOTO25cqo as a type-Ia SN
  8. GRB 250515A:COLIBRÍ optical observations of the GOTO candidate
  9. Swift GRB 250516A: Global MASTER-Net observations report
  10. GRB 250515A: 1.6m Mephisto optical detection
  11. GRB 250516A: AstroSat CZTI detection
  12. GRB 250515A/GOTO25cqo: SVOM/VT optical blue color
  13. GRB 250516A: Fermi GBM Observation
  14. GRB 250516A: Swift/UVOT Detection
  15. GRB 250515A: Swift ToO observations
  16. GRB 250512B / EP250512a: SVOM/GRM analysis
  17. GRB 250515A: GOTO candidate optical counterpart
  18. GRB 250424A: COLIBRÍ detection of the associated supernova
  19. Konus-Wind detection of GRB 250512B / EP250512a
  20. GRB 250502A: TESS observations
  21. GRB 250509A: Swift-BAT refined analysis
  22. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Final Epochs)
  23. Fermi GRB 250512A: Global MASTER-Net observations report
  24. Konus-Wind detection of GRB 250506A
  25. EP250512a/GRB 250512B: REM optical/NIR observations
  26. EP250511a: Koshka Zeiss-1000 Optical Upper Limit
  27. GRB 250507B: AstroSat CZTI detection
  28. EP250511a: Gemini optical counterpart observation
  29. EP250512a/GRB 250512B refined analysis of the EP-WXT and EP-FXT observations
  30. EP250512a/GRB 250512B: FTW optical and NIR observations of the counterpart
  31. EP250512a: Global MASTER-Net observations report
  32. EP250511a: FTW optical and NIR observations
  33. GRB 250512B/EP250512a: SVOM/VT optical fading
  34. GRB 250512B/EP250512a：SVOM/VT bright optical counterpart
  35. EP250511a: Mephisto optical upper limits
  36. GRB 250506A: GRBAlpha detection
  37. GRB 250512B: SVOM detection of a burst
  38. EP250511a: REM optical/NIR observations
  39. EP250511a: Einstein Probe follow-up obsevation and refined analysis
  40. EP250511a: SVOM/VT optical candidate comfirmation
  41. EP250511a: Global MASTER-Net observations report
  42. EP250511a: COLIBRÍ optical counterpart candidate
  43. EP250511a: BOOTES-5 optical upper limit
  44. EP250508a: Gemini NIR upper limits
  45. GRB 250510B: Fermi GBM Observation
  46. Fermi GRB 250510C: Global MASTER-Net observations report
  47. Fermi GRB 250510B: Global MASTER-Net observations report
  48. GRB 250510A: Swift-XRT observations
  49. GRB 250509A: Fermi GBM Observation
  50. IceCube-250506A: No Transient Candidates from the Zwicky Transient Facility
  51. GRB 250510A: follow-up observation with EP-FXT
  52. GRB 250510B: Swift/BAT-GUANO localization skymap of a burst
  53. GRB 250510A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  54. GRB 250507A: J-band observations with WINTER (duplicate submission)
  55. GRB 250507A: J-band observations with WINTER
  56. EP250508a: SVOM/VT optical candidate fading
  57. Fermi GRB 250509A: Global MASTER-Net observations report
  58. Swift GRB 250509A: Global MASTER-Net observations report
  59. GRB 250506A: NOT optical upper limits
  60. EP250508a: Liverpool Telescope optical upper limits
  61. EP250508a: follow-up observation with EP-FXT
  62. EP250508a: SVOM/VT optical candidate
  63. EP250508a: KAIT optical upper limit
  64. GRB 250507A: KAIT optical upper limit
  65. EP250508a: refined analysis of the EP-WXT and EP-FXT observations
  66. GRB 250502A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  67. GRB 250506A: GECAM detection
  68. EP250508a: REM optical/NIR observations
  69. EP250508a: Global MASTER-Net observations report
  70. GRB 250506A: SVOM/VT optical upper limit
  71. EP250508a: COLIBRÍ Optical Limit
  72. GRB 250507A: Swift-XRT refined Analysis
  73. IceCube-250506A: Upper limits from a search for additional neutrino events in IceCube
  74. GRB 250506A: Swift/UVOT Upper Limits
  75. GRB 250507A: follow-up observation with EP-FXT
  76. GRB 250430A / EP250430a: AstroSat CZTI detection
  77. EP#01709175213/IGR J19566+0326: Swift-XRT detection
  78. GRB 250506A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  79. GRB 250507A: refined SVOM/MXT data analysis
  80. GRB 250507A: REM optical/NIR observations
  81. GRB 250507A: SVOM/VT optical upper limit
  82. GRB 250506A: Swift-XRT observations
  83. Fermi-LAT Gamma-ray Observations of IceCube-250506A
  84. GRB 250507A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  85. GRB 250506A: Mephisto optical upper limits
  86. GRB 250504A: EIRSAT-1 GMOD Detection
  87. GRB 250506A: Swift ToO observations
  88. GRB 250502A: Bassano Bresciano Observatory upper limit
  89. GRB 250430A: Konus-Wind detection and joint Konus-Wind+Swift-BAT spectral analysis
  90. GRB 250506A: Xinglong 2.16m optical upper limit
  91. SVOM/sb25050601: EP-FXT observations
  92. GRB 250506A: SVOM improved position and MXT detection of a fading X-ray afterglow
  93. GRB 250506A: REM optical/NIR upper limits
  94. GRB 250506A: Fermi GBM Observation
  95. GRB 250506A: Swift XRT observations and possible counterpart detection
  96. GRB 250506A: TRT optical observations
  97. GRB 250506A: SVOM/COLIBRÍ (FM-GFT) Upper Limits on the Optical Counterpart
  98. GRB 250504A: Swift-BAT refined analysis
  99. GRB 250430A: Swift-BAT refined analysis
  100. GRB 250504A: VLT/X-shooter upper limits

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