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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"

3384 results found.

  1. EP250612a / GRB 250612B: SVOM/VT optical candidate
  2. EP250612a: Global MASTER-Net observations report
  3. EP250612a/GRB 250612B: JinShan optical upper limit
  4. EP 250612a: AST3-3 Yaoan Optical Observation
  5. EP250610a: Upper limit from Fermi-GBM Observations
  6. GRB 250612B: BALROG localization (Fermi Trigger 771424081 / GRB 250612519)
  7. EP250612a: Einstein Probe detection of an X-ray transient
  8. EP250610a: continuous follow-up observations with EP-FXT
  9. EP250610A: Swift/UVOT Upper limits
  10. EP250610a: TNG NIR upper limit
  11. GRB 250610B: Fermi/GBM sub-threshold detection of a possibly hard burst
  12. GRB 250610B: EP-FXT follow-up observation and afterglow counterpart
  13. EP250610a: Global MASTER-Net observations report
  14. EP250610a: refined analysis of the EP-WXT and EP-FXT observations
  15. EP250610a: SVOM/VT optical upper limit
  16. EP250610a: REM optical/NIR observations
  17. EP250610a: Swift-XRT counterpart detection
  18. EP250610a: COLIBRÍ optical upper limit
  19. EP250610a: Einstein Probe detection of an X-ray transient
  20. The EP-WXT trigger 01709178283 is likely a flaring star
  21. EP-WXT trigger 01709178244: confirmation of a stellar flare by BOOTES-5 & BOOTES-7
  22. The EP-WXT trigger 01709178244 is likely a flaring star
  23. EP-WXT trigger 01709178069: confirmation of a stellar flare by BOOTES-6 & BOOTES-7
  24. The EP-WXT trigger 01709178069 is likely a flaring star
  25. EP/WXT 01709177873: GOTO observations confirm stellar variability
  26. The EP-WXT trigger 01709177873 is likely a flaring star
  27. Konus-Wind detection of GRB 250601A
  28. The EP-WXT trigger 01709177837 is likely a flaring star
  29. GRB 250601A: PRIME H band upper limit.
  30. GRB 250601A: PRIME J band upper limit.
  31. GRB 250601A: VLT/FORS2 Optical Observation
  32. GRB 250601A: EP-FXT follow-up observation and afterglow candidates
  33. EP#01709177494: SVOM/VT optical observations
  34. EP#01709177494: Swift-XRT counterpart detection of known source
  35. GRB 250530A: EP-FXT counterpart detection
  36. EP J1350.0-8622: EP-FXT follow-up observation
  37. EP-WXT trigger 01709177124: confirmation of a stellar flare by BOOTES-6
  38. The EP-WXT trigger 01709177124 is likely a flaring star
  39. EP250526a: SVOM/VT optical upper limit
  40. EP250526a: refined analysis of the EP-WXT and EP-FXT observations
  41. EP250526a: COLIBRÍ optical upper limits
  42. EP250526a: Global MASTER-Net observations report
  43. EP250526a: Einstein Probe detection of a fast X-ray transient
  44. EP J1350.0-8622: BOOTES-6/DPRT optical upper limit
  45. EP J1350.0-8622: Einstein Probe detection of an X-ray transient candidate
  46. EP-WXT trigger 01709176712: SVOM/C-GFT observations of blue-to-red color variation
  47. EP-WXT trigger 01709176712: GOTO observations confirm stellar counterpart variability
  48. The EP-WXT trigger 01709176712 is likely a flaring star
  49. GRB 250521B: SVOM/VT optical upper limit
  50. The EP-WXT trigger 01709176612: SVOM/VT optical observations
  51. The EP-WXT trigger 01709176612: refined analysis of the EP-FXT observation
  52. GRB 250521B: EP-FXT follow-up observation and afterglow candidates
  53. EP#01709176612: Swift-XRT counterpart detection of flaring star
  54. The EP-WXT trigger 01709176612 is likely a flaring star
  55. Konus-Wind detection of GRB 250520A (short/hard)
  56. Konus-Wind detection of GRB 250516B
  57. Konus-Wind detection of GRB 250516A
  58. EP-WXT trigger (ID: 01709176312): a new X-ray outburst of HMXB RX J0111.2-7317
  59. Konus-Wind detection of GRB 250512B / EP250512a
  60. Konus-Wind detection of GRB 250506A
  61. EP250512a/GRB 250512B: REM optical/NIR observations
  62. EP250511a: Gemini optical counterpart observation
  63. EP250512a/GRB 250512B refined analysis of the EP-WXT and EP-FXT observations
  64. EP250512a: Global MASTER-Net observations report
  65. GRB 250512B/EP250512a：SVOM/VT bright optical counterpart
  66. GRB 250512B: SVOM detection of a burst
  67. EP250512a: Einstein Probe detection of an X-ray transient
  68. EP250511a: REM optical/NIR observations
  69. EP250511a: Einstein Probe follow-up obsevation and refined analysis
  70. EP250511a: SVOM/VT optical candidate comfirmation
  71. EP250511a: Global MASTER-Net observations report
  72. EP250511a: COLIBRÍ optical counterpart candidate
  73. EP250511a: BOOTES-5 optical upper limit
  74. EP250511a: Einstein Probe detection of an X-ray transient
  75. EP250508a: Gemini NIR upper limits
  76. GRB 250510A: Swift-XRT observations
  77. GRB 250510A: follow-up observation with EP-FXT
  78. GRB 250507A: J-band observations with WINTER
  79. EP250508a: SVOM/VT optical candidate fading
  80. GRB 250506A: NOT optical upper limits
  81. EP250508a: Liverpool Telescope optical upper limits
  82. EP250508a: follow-up observation with EP-FXT
  83. EP250508a: SVOM/VT optical candidate
  84. EP250508a: refined analysis of the EP-WXT and EP-FXT observations
  85. EP250508a: REM optical/NIR observations
  86. EP250508a: Global MASTER-Net observations report
  87. GRB 250506A: SVOM/VT optical upper limit
  88. EP250508a: Einstein Probe detection of an X-ray transient
  89. GRB 250507A: Swift-XRT refined Analysis
  90. GRB 250507A: follow-up observation with EP-FXT
  91. GRB 250430A / EP250430a: AstroSat CZTI detection
  92. EP#01709175213/IGR J19566+0326: Swift-XRT detection
  93. EP-WXT trigger 01709175213: a new X-ray outburst of LMXB MAXI J1957+032
  94. GRB 250430A: Konus-Wind detection and joint Konus-Wind+Swift-BAT spectral analysis
  95. GRB 250506A: Xinglong 2.16m optical upper limit
  96. SVOM/sb25050601: EP-FXT observations
  97. EP250428b: Pan-STARRS follow-up, upper limit on the optical counterpart, and possible host galaxy.
  98. GRB 250430A: NUTTelA-TAO Early Measurements
  99. SVOM/sb25043004: EP-FXT observations
  100. EP250430a/GRB 250430A: Einstein Probe WXT detection of the X-ray prompt emission

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