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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"

28122 results found.

  1. GRB 250527D: Swift/BAT-GUANO localization skymap of a burst
  2. GRB 250527B: Swift-XRT observations
  3. GRB 250520A: Swift-BAT refined analysis
  4. GRB 250527C: Swift/BAT-GUANO arcminute localization of a burst
  5. GRB 250521D: SVOM/GRM analysis suggests a possible “long” duration type I burst
  6. GRB 250527B / MAXI J1450-527 : MAXI/GSC detection
  7. EP250526a: refined analysis of the EP-WXT and EP-FXT observations
  8. GRB 250314A: CIDER NB1008 upper limit
  9. EP250526a: COLIBRÍ optical upper limits
  10. EP250526a: Einstein Probe detection of a fast X-ray transient
  11. EP J1350.0-8622: Einstein Probe detection of an X-ray transient candidate
  12. EP-WXT trigger 01709176712: SVOM/C-GFT observations of blue-to-red color variation
  13. GRB 250523A: BALROG localization (Fermi Trigger 769703188 / GRB 250523602)
  14. The EP-WXT trigger 01709176612: SVOM/VT optical observations
  15. EP#01709176612: Swift-XRT counterpart detection of flaring star
  16. GRB 250521D: DDOTI Optical Upper Limit
  17. GRB 250521B: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  18. GRB 250521D: LAST tentative optical counterpart candidate
  19. GRB 250521A: DDOTI Optical Upper Limit
  20. GRB 250520A: VLT/FORS2 Optical Observation
  21. GRB 250502A: Tautenburg observations
  22. GRB 250520A: Swift/UVOT Upper Limits
  23. IPN triangulation of GRB 250516B
  24. GRB 250520A: J-band observations with WINTER
  25. GRB 250520A: Gemini-South optical observations
  26. GRB 250520A: Swift-XRT refined Analysis
  27. GRB 250520A: REM optical/NIR early observations
  28. GRB 250520A：SVOM/VT optical candidate
  29. GRB 250520A: COLIBRÍ optical upper limit
  30. GRB 250520A: DDOTI Optical Upper Limit
  31. GRB 250520A: AstroSat CZTI detection of a short burst
  32. GRB 250520A: Enhanced Swift-XRT position
  33. GRB 250520A: Swift detection of a burst
  34. GRB 250516A: Swift-BAT refined analysis
  35. GRB 250516A: COLIBRÍ optical upper limit
  36. EP-WXT trigger (ID: 01709176312): a new X-ray outburst of HMXB RX J0111.2-7317
  37. GRB 250515A: Swift-XRT observations
  38. GRB 250515A:COLIBRÍ optical observations of the GOTO candidate
  39. GRB 250515A: 1.6m Mephisto optical detection
  40. GRB 250516A: Fermi GBM Observation
  41. GRB 250516A: Swift-XRT refined Analysis
  42. GRB 250516A: Swift/UVOT Detection
  43. GRB 250516B: GECAM-B detection of a bright long burst
  44. GRB 250516A: Enhanced Swift-XRT position
  45. GRB 250516A: Swift detection of a burst
  46. MAXI GRB250515.65: Global MASTER-Net observations report
  47. GRB 250424A: COLIBRÍ detection of the associated supernova
  48. GRB 250502A: TESS observations
  49. GRB 250509A: Swift-BAT refined analysis
  50. Fermi GRB 250512A: Global MASTER-Net observations report
  51. EP250512a/GRB 250512B: REM optical/NIR observations
  52. EP250511a: Koshka Zeiss-1000 Optical Upper Limit
  53. GRB 250507B: AstroSat CZTI detection
  54. EP250511a: Gemini optical counterpart observation
  55. EP250512a/GRB 250512B refined analysis of the EP-WXT and EP-FXT observations
  56. EP250511a: Mephisto optical upper limits
  57. GRB 250512B: SVOM detection of a burst
  58. EP250512a: Einstein Probe detection of an X-ray transient
  59. EP250511a: REM optical/NIR observations
  60. EP250511a: Einstein Probe follow-up obsevation and refined analysis
  61. EP250511a: COLIBRÍ optical counterpart candidate
  62. EP250511a: BOOTES-5 optical upper limit
  63. EP250511a: Einstein Probe detection of an X-ray transient
  64. EP250508a: Gemini NIR upper limits
  65. GRB 250510B: Fermi GBM Observation
  66. GRB 250510A: Swift-XRT observations
  67. GRB 250509A: Fermi GBM Observation
  68. IceCube-250506A: No Transient Candidates from the Zwicky Transient Facility
  69. GRB 250510B: Swift/BAT-GUANO localization skymap of a burst
  70. GRB 250510A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  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: Swift detection of a burst
  76. GRB 250506A: NOT optical upper limits
  77. EP250508a: Liverpool Telescope optical upper limits
  78. EP250508a: KAIT optical upper limit
  79. GRB 250507A: KAIT optical upper limit
  80. EP250508a: refined analysis of the EP-WXT and EP-FXT observations
  81. GRB 250505B: SVOM/GRM observation of a short burst
  82. GRB 250502A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  83. EP250508a: REM optical/NIR observations
  84. GRB 250506A: Swift-XRT afterglow detection
  85. EP250508a: COLIBRÍ Optical Limit
  86. EP250508a: Einstein Probe detection of an X-ray transient
  87. GRB 250507A: Swift-XRT refined Analysis
  88. IceCube-250506A: Upper limits from a search for additional neutrino events in IceCube
  89. GRB 250506A: Swift/UVOT Upper Limits
  90. GRB 250507A: follow-up observation with EP-FXT
  91. GRB 250506A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  92. GRB 250507A: REM optical/NIR observations
  93. GRB 250507A: SVOM/VT optical upper limit
  94. GRB 250506A: Swift-XRT observations
  95. Fermi-LAT Gamma-ray Observations of IceCube-250506A
  96. GRB 250507A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  97. EP-WXT trigger 01709175213: a new X-ray outburst of LMXB MAXI J1957+032
  98. GRB 250507A: SVOM detection of a long burst
  99. GRB 250506A: Mephisto optical upper limits
  100. GRB 250504A: EIRSAT-1 GMOD Detection

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