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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"

26712 results found.

  1. GRB 250605A: Swift-XRT refined Analysis
  2. GRB 250605A: Enhanced Swift-XRT position
  3. The EP-WXT trigger 01709177873 is likely a flaring star
  4. GRB 250605A: LT optical observations
  5. GRB 250605A: Swift detection of a burst
  6. Konus-Wind detection of GRB 250601A
  7. IPN triangulation of GRB 250404B
  8. IPN triangulation of GRB 250529A
  9. The EP-WXT trigger 01709177837 is likely a flaring star
  10. GRB 250601A: PRIME H band upper limit.
  11. GRB 250530A: SVOM/GRM analysis
  12. GRB 250601A: PRIME J band upper limit.
  13. GRB 250601A: VLT/FORS2 Optical Observation
  14. GRB 250601A: Fermi GBM Observation
  15. GRB 250602A: DDOTI Optical Follow-Up of the Fermi/LAT Localization
  16. GRB 250603A: Swift/UVOT Upper Limits
  17. GRB 250603A: Swift-XRT refined Analysis
  18. GRB 250603A: Enhanced Swift-XRT position
  19. GRB 250603A: Swift-XRT position and confirmation of GRB nature
  20. Swift GRB250603.05: Global MASTER-Net observations report
  21. GRB 250603A: Swift detection of a burst or new Galactic transient Swift J0839.7-3916
  22. GRB 250602A: Fermi GBM Observation
  23. GRB 250602A: DDOTI Optical Upper Limit
  24. GRB 250601A: EP-FXT follow-up observation and afterglow candidates
  25. GRB 250601A: Swift/XRT candidate afterglow
  26. GRB 250601A: Swift-XRT observations
  27. GRB 250602A: Fermi GBM Final Real-time Localization
  28. EP#01709177494: SVOM/VT optical observations
  29. EP#01709177494: Swift-XRT counterpart detection of known source
  30. GRB 250521C/ZTF25aarhkyn/AT2025mgj: COLIBRÍ optical observations
  31. GRB 250530C: Swift-XRT refined Analysis
  32. GRB 250530A: TNG detection of a NIR source inside the Swift/XRT error circle
  33. GRB 250530C: Enhanced Swift-XRT position
  34. GRB 250530C: Swift detection of a burst
  35. GRB 250530A: EP-FXT counterpart detection
  36. GRB 250530A: SVOM/VT optical upper limit
  37. GRB 250530A: Swift-XRT counterpart detection
  38. GRB 250530A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate retraction and detection limit
  39. GRB 250530A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  40. GRB 250530A: SVOM detection of a burst
  41. GRB 250527C: Swift/UVOT Upper Limits
  42. GRB 250527D: Swift/BAT-GUANO localization skymap of a burst
  43. EP J1350.0-8622: EP-FXT follow-up observation
  44. GRB 250527B: Swift-XRT observations
  45. EP-WXT trigger 01709177124: confirmation of a stellar flare by BOOTES-6
  46. The EP-WXT trigger 01709177124 is likely a flaring star
  47. GRB 250521D: SVOM/GRM analysis suggests a possible “long” duration type I burst
  48. GRB 250527A: Fermi GBM Final Localization
  49. EP250526a: refined analysis of the EP-WXT and EP-FXT observations
  50. GRB 250314A: CIDER NB1008 upper limit
  51. EP250526a: COLIBRÍ optical upper limits
  52. EP250526a: Einstein Probe detection of a fast X-ray transient
  53. EP J1350.0-8622: Einstein Probe detection of an X-ray transient candidate
  54. EP-WXT trigger 01709176712: SVOM/C-GFT observations of blue-to-red color variation
  55. GRB 250520A: 3 GHz MeerKAT Detection
  56. The EP-WXT trigger 01709176712 is likely a flaring star
  57. The EP-WXT trigger 01709176612: SVOM/VT optical observations
  58. GRB 250521B: EP-FXT follow-up observation and afterglow candidates
  59. EP#01709176612: Swift-XRT counterpart detection of flaring star
  60. GRB 250521D: DDOTI Optical Upper Limit
  61. The EP-WXT trigger 01709176612 is likely a flaring star
  62. GRB 250521B: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  63. GRB 250521D: LAST tentative optical counterpart candidate
  64. GRB 250520A: 10 GHz VLA radio source
  65. GRB 250521A: DDOTI Optical Upper Limit
  66. Konus-Wind detection of GRB 250520A (short/hard)
  67. GRB 250520A: VLT/FORS2 Optical Observation
  68. GRB 250502A: Tautenburg observations
  69. GRB 250520A: Swift/UVOT Upper Limits
  70. IPN triangulation of GRB 250516B
  71. GRB 250520A: J-band observations with WINTER
  72. GRB 250520A: Gemini-South optical observations
  73. GRB 250520A: Swift-XRT refined Analysis
  74. GRB 250520A: REM optical/NIR early observations
  75. GRB 250520A：SVOM/VT optical candidate
  76. GRB 250520A: COLIBRÍ optical upper limit
  77. GRB 250520A: DDOTI Optical Upper Limit
  78. GRB 250520A: SVOM/GRM observation
  79. GRB 250520A: Enhanced Swift-XRT position
  80. GRB 250520A: Swift detection of a burst
  81. GRB 250516A: COLIBRÍ optical upper limit
  82. Konus-Wind detection of GRB 250516A
  83. EP-WXT trigger (ID: 01709176312): a new X-ray outburst of HMXB RX J0111.2-7317
  84. GRB 250515A: Swift-XRT observations
  85. GRB 250515A:COLIBRÍ optical observations of the GOTO candidate
  86. GRB 250515A: 1.6m Mephisto optical detection
  87. GRB 250516A: Fermi GBM Observation
  88. GRB 250516A: Swift-XRT refined Analysis
  89. GRB 250516A: Swift/UVOT Detection
  90. GRB 250516B: GECAM-B detection of a bright long burst
  91. GRB 250516A: Enhanced Swift-XRT position
  92. GRB 250516A: Swift detection of a burst
  93. GRB 250512B / EP250512a: SVOM/GRM analysis
  94. GRB 250424A: COLIBRÍ detection of the associated supernova
  95. Konus-Wind detection of GRB 250512B / EP250512a
  96. GRB 250502A: TESS observations
  97. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Final Epochs)
  98. Konus-Wind detection of GRB 250506A
  99. EP250512a/GRB 250512B: REM optical/NIR observations
  100. EP250511a: Koshka Zeiss-1000 Optical Upper Limit

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