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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"

12170 results found.

  1. GRB 250617B: Assy AZT-20 Optical Observations
  2. GRB 250615A/EP250615a: FTW optical and NIR observations
  3. sb25061218/SVOM: OHP/T120 and OHP/T193 optical imaging and spectroscopic observations
  4. GRB 250617B: COLIBRÍ optical observations
  5. GRB 250617B: Swift-XRT refined Analysis
  6. GRB 250617B: Swift detection of a burst with an optical counterpart
  7. EP#01709178975: Swift-XRT counterpart detection
  8. Konus-Wind detection of GRB 250615A / EP250615a
  9. GRB 250615A / EP250615a: AstroSat CZTI detection
  10. Konus-Wind detection of GRB 250612C (short/hard with extended emission)
  11. Fermi trigger No 771752663: Global MASTER-Net observations report
  12. sb25061218: Swift-XRT observations
  13. GRB 250610B: J band upper limit by SYSU 80cm infrared telescope
  14. EP250612a / GRB 250612B: SVOM/VT optical candidate
  15. sb25061207: Swift-XRT observations
  16. GRB 250610B: Swift-XRT refined Analysis
  17. EP250612a: Einstein Probe detection of an X-ray transient
  18. GRB 250610B: MISTRAL/T193 and T120 OHP further observations
  19. sb25061207: SVOM detection of a X-ray transient
  20. Swift GRB250612.04: Global MASTER-Net observations report
  21. GRB 250610B: Swift-XRT counterpart detection
  22. GRB 250610B: SVOM/VT optical counterpart
  23. GRB 250610B: OHP/T120 optical counterpart candidate
  24. GRB 250610B: GOTO optical upper limit
  25. EP250610a: Global MASTER-Net observations report
  26. GRB 250610B: SVOM detection of a long burst
  27. EP250610a: Swift-XRT counterpart detection
  28. EP250610a: Einstein Probe detection of an X-ray transient
  29. Fermi trigger No 771072240: Global MASTER-Net observations report
  30. GRB 250609A: Swift/BAT-GUANO localization skymap of a likely short burst
  31. GRB 250529A: GOTO optical counterpart candidate (GOTO25dea/AT 2025ndt)
  32. GRB 250605A: Swift-XRT refined Analysis
  33. Fermi GRB 250606A: Global MASTER-Net observations report
  34. Fermi trigger No 770867684: Global MASTER-Net observations report
  35. GRB 250605A: LT optical observations
  36. Konus-Wind detection of GRB 250601A
  37. Fermi Gamma-ray Burst Monitor trigger 770675211/250603852 is not a GRB
  38. Swift GRB250603.05: Global MASTER-Net observations report
  39. GRB 250602A: Fermi-LAT detection
  40. GRB 250530A: VLT/HAWK-I NIR counterpart fading
  41. Fermi GRB 250531A: Global MASTER-Net observations report
  42. EP#01709177494: Swift-XRT counterpart detection of known source
  43. GRB 250530C: Swift-XRT refined Analysis
  44. GRB 250530C: Swift detection of a burst
  45. GRB 250530A: Swift-XRT counterpart detection
  46. GRB 250527D: Swift/BAT-GUANO localization skymap of a burst
  47. EP J1350.0-8622: EP-FXT follow-up observation
  48. Fermi trigger No 770058372: Global MASTER-Net observations report
  49. GRB 250527B / MAXI J1450-527 : MAXI/GSC detection
  50. EP250526a: refined analysis of the EP-WXT and EP-FXT observations
  51. GRB 250314A: CIDER NB1008 upper limit
  52. EP J1350.0-8622: Einstein Probe detection of an X-ray transient candidate
  53. Fermi GRB 250523A: Global MASTER-Net observations report
  54. Fermi trigger No 769611916: Global MASTER-Net observations report
  55. EP-WXT trigger 01709176712: GOTO observations confirm stellar counterpart variability
  56. GRB 250520A: GRBAlpha detection
  57. EP#01709176612: Swift-XRT counterpart detection of flaring star
  58. Fermi trigger No 769533898: Global MASTER-Net observations report
  59. GRB 250521D: LAST tentative optical counterpart candidate
  60. GRB 250520A: CALET Gamma-Ray Burst Monitor detection
  61. Konus-Wind detection of GRB 250520A (short/hard)
  62. Konus-Wind detection of GRB 250516B
  63. GRB 250520A: Gemini-South optical observations
  64. GRB 250520A: REM optical/NIR early observations
  65. GRB 250520B: Fermi GBM Final Real-time Localization
  66. GRB 250520A: COLIBRÍ optical upper limit
  67. GRB 250520A: DDOTI Optical Upper Limit
  68. GRB 250520A: AstroSat CZTI detection of a short burst
  69. GRB 250520A: GOTO optical upper limit
  70. Swift GRB 250520A: Global MASTER-Net observations report
  71. GRB 250516A: Swift-BAT refined analysis
  72. GRB 250516A: COLIBRÍ optical upper limit
  73. Konus-Wind detection of GRB 250516A
  74. Fermi GRB 250516A: Global MASTER-Net observations report
  75. GRB 250515A/GOTO25cqo: SVOM/VT optical blue color
  76. GRB 250516A: Swift-XRT refined Analysis
  77. GRB 250516A: Swift detection of a burst
  78. GRB 250512B / EP250512a: SVOM/GRM analysis
  79. GRB 250515A: GOTO candidate optical counterpart
  80. GRB 250515A: Fermi GBM Final Localization
  81. Konus-Wind detection of GRB 250512B / EP250512a
  82. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Final Epochs)
  83. Konus-Wind detection of GRB 250506A
  84. GRB 250507B: AstroSat CZTI detection
  85. EP250512a/GRB 250512B refined analysis of the EP-WXT and EP-FXT observations
  86. EP250512a: Global MASTER-Net observations report
  87. GRB 250512B/EP250512a:SVOM/VT bright optical counterpart
  88. GRB 250512B: SVOM detection of a burst
  89. EP250512a: Einstein Probe detection of an X-ray transient
  90. EP250511a: Einstein Probe follow-up obsevation and refined analysis
  91. EP250511a: Global MASTER-Net observations report
  92. EP250511a: Einstein Probe detection of an X-ray transient
  93. Fermi GRB 250510C: Global MASTER-Net observations report
  94. GRB 250510B: Swift/BAT-GUANO localization skymap of a burst
  95. GRB 250510A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  96. GRB 250509A: Swift-XRT refined Analysis
  97. GRB 250510A: SVOM possible detection of a burst
  98. Fermi GRB 250509A: Global MASTER-Net observations report
  99. GRB 250509A: Swift detection of a burst
  100. EP250508a: refined analysis of the EP-WXT and EP-FXT observations

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