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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"

32692 results found.

  1. GRB 250520A: VLT/FORS2 Optical Observation
  2. GRB 250502A: Tautenburg observations
  3. GRB 250520A: Swift/UVOT Upper Limits
  4. Konus-Wind detection of GRB 250516B
  5. IPN triangulation of GRB 250516B
  6. GRB 250520A: J-band observations with WINTER
  7. GRB 250520A: Gemini-South optical observations
  8. GRB 250520A: REM optical/NIR early observations
  9. GRB 250520A:SVOM/VT optical candidate
  10. GRB 250520A: COLIBRÍ optical upper limit
  11. GRB 250520A: DDOTI Optical Upper Limit
  12. GRB 250520A: AstroSat CZTI detection of a short burst
  13. GRB 250516B: GRBAlpha detection
  14. GRB 250520A: SVOM/GRM observation
  15. GRB 250520A: GOTO optical upper limit
  16. GRB 250516B: Insight-HXMT detection
  17. EP250427a/GRB250427A: VLA Detection of Radio Counterpart
  18. GRB 250516A: Swift-BAT refined analysis
  19. GRB 250516A: COLIBRÍ optical upper limit
  20. Konus-Wind detection of GRB 250516A
  21. GRB 250516B: NuSTAR Detection of the Prompt Emission
  22. Fermi GRB 250516A: Global MASTER-Net observations report
  23. GRB 250515A: Swift-XRT observations
  24. GRB 250515A: NOT classification of GOTO25cqo as a type-Ia SN
  25. GRB 250515A:COLIBRÍ optical observations of the GOTO candidate
  26. Swift GRB 250516A: Global MASTER-Net observations report
  27. GRB 250515A: 1.6m Mephisto optical detection
  28. GRB 250516A: AstroSat CZTI detection
  29. GRB 250515A/GOTO25cqo: SVOM/VT optical blue color
  30. GRB 250516A: Fermi GBM Observation
  31. GRB 250516A: Swift/UVOT Detection
  32. GRB 250515A: Swift ToO observations
  33. GRB 250512B / EP250512a: SVOM/GRM analysis
  34. GRB 250515A: GOTO candidate optical counterpart
  35. GRB 250424A: COLIBRÍ detection of the associated supernova
  36. Konus-Wind detection of GRB 250512B / EP250512a
  37. GRB 250502A: TESS observations
  38. GRB 250509A: Swift-BAT refined analysis
  39. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Final Epochs)
  40. Fermi GRB 250512A: Global MASTER-Net observations report
  41. Konus-Wind detection of GRB 250506A
  42. EP250512a/GRB 250512B: REM optical/NIR observations
  43. EP250511a: Koshka Zeiss-1000 Optical Upper Limit
  44. GRB 250507B: AstroSat CZTI detection
  45. EP250511a: Gemini optical counterpart observation
  46. EP250512a/GRB 250512B refined analysis of the EP-WXT and EP-FXT observations
  47. EP250512a/GRB 250512B: FTW optical and NIR observations of the counterpart
  48. EP250512a: Global MASTER-Net observations report
  49. EP250511a: FTW optical and NIR observations
  50. GRB 250512B/EP250512a: SVOM/VT optical fading
  51. GRB 250512B/EP250512a:SVOM/VT bright optical counterpart
  52. EP250511a: Mephisto optical upper limits
  53. GRB 250506A: GRBAlpha detection
  54. GRB 250512B: SVOM detection of a burst
  55. EP250511a: REM optical/NIR observations
  56. EP250511a: Einstein Probe follow-up obsevation and refined analysis
  57. EP250511a: SVOM/VT optical candidate comfirmation
  58. EP250511a: Global MASTER-Net observations report
  59. EP250511a: COLIBRÍ optical counterpart candidate
  60. EP250511a: BOOTES-5 optical upper limit
  61. EP250508a: Gemini NIR upper limits
  62. GRB 250510B: Fermi GBM Observation
  63. Fermi GRB 250510C: Global MASTER-Net observations report
  64. Fermi GRB 250510B: Global MASTER-Net observations report
  65. GRB 250510A: Swift-XRT observations
  66. GRB 250509A: Fermi GBM Observation
  67. IceCube-250506A: No Transient Candidates from the Zwicky Transient Facility
  68. GRB 250510A: follow-up observation with EP-FXT
  69. GRB 250510B: Swift/BAT-GUANO localization skymap of a burst
  70. GRB 250510A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  71. GRB 250507A: J-band observations with WINTER (duplicate submission)
  72. GRB 250507A: J-band observations with WINTER
  73. EP250508a: SVOM/VT optical candidate fading
  74. Fermi GRB 250509A: Global MASTER-Net observations report
  75. Swift GRB 250509A: Global MASTER-Net observations report
  76. GRB 250506A: NOT optical upper limits
  77. EP250508a: Liverpool Telescope optical upper limits
  78. EP250508a: follow-up observation with EP-FXT
  79. EP250508a: SVOM/VT optical candidate
  80. EP250508a: KAIT optical upper limit
  81. GRB 250507A: KAIT optical upper limit
  82. EP250508a: refined analysis of the EP-WXT and EP-FXT observations
  83. GRB 250502A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  84. GRB 250506A: GECAM detection
  85. EP250508a: REM optical/NIR observations
  86. EP250508a: Global MASTER-Net observations report
  87. GRB 250506A: SVOM/VT optical upper limit
  88. EP250508a: COLIBRÍ Optical Limit
  89. GRB 250507A: Swift-XRT refined Analysis
  90. IceCube-250506A: Upper limits from a search for additional neutrino events in IceCube
  91. GRB 250506A: Swift/UVOT Upper Limits
  92. GRB 250507A: follow-up observation with EP-FXT
  93. GRB 250430A / EP250430a: AstroSat CZTI detection
  94. EP#01709175213/IGR J19566+0326: Swift-XRT detection
  95. GRB 250506A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  96. GRB 250507A: refined SVOM/MXT data analysis
  97. GRB 250507A: REM optical/NIR observations
  98. GRB 250507A: SVOM/VT optical upper limit
  99. GRB 250506A: Swift-XRT observations
  100. Fermi-LAT Gamma-ray Observations of IceCube-250506A

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