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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. EP250806a: Earlier Detection of the VT Candidate by COLIBRÍ and LS
  2. EP250806a: SVOM /VT optical candidate
  3. EP250806a: COLIBRÍ optical upper limit
  4. EP250806a: Einstein Probe detection of an X-ray transient
  5. EP250730a: SVOM/VT optical upper limit
  6. EP250802a: Liverpool Telescope optical upper limits
  7. EP250802a: Global MASTER-Net observations report
  8. EP250802a: GROWTH-India Telescope optical upper limit
  9. EP250802a: Einstein Probe detection of an X-ray transient
  10. The EP-WXT trigger 01709198251 is likely a flaring star
  11. The EP-WXT trigger 01709198202 is likely a flaring star
  12. EP250711a: CrAO and Assy optical observations
  13. EP250730a: Global MASTER-Net observations report
  14. EP250730a: COLIBRÍ optical upper limit
  15. GRB 250727A: Swift-XRT afterglow confirmation and refined analysis
  16. EP250730a: Einstein Probe detection of an X-ray transient
  17. GRB 250727A: EP-FXT follow-up observation
  18. EP-WXT trigger 01709195487: confirmation of a stellar flare by BOOTES-6 & BOOTES-7
  19. GRB 250727A: EP-FXT counterpart detection
  20. The EP-WXT trigger 01709195487 is likely a flaring star
  21. Konus-Wind detection of GRB 250725A
  22. EP250702a/GRB250702B,D,E: SVOM/VT optical upper limit
  23. GRB 270713A: Kitab and AbAO Optical Observations
  24. Konus-Wind detection of GRB 250716A
  25. GRB 250702B,D,E / EP250702a: H.E.S.S. very-high-energy gamma-ray observations
  26. GRB 250713A: Mephisto optical upper limits
  27. GRB 250713A: SVOM/VT optical upper limit
  28. GRB 250713A: NOT optical upper limits
  29. GRB 250713A: SVOM/C-GFT upper limit
  30. GRB 250713A: Swift-XRT observations
  31. GRB 250713A: EP-FXT counterpart detection
  32. EP250711a: Global MASTER-Net observations report
  33. EP250711a: NOT optical counterpart candidate
  34. EP250711a: EP-WXT detection and FXT follow-up observation of a fast X-ray transient
  35. EP candidate (ID=08500000365): COLIBRÍ optical Upper limit
  36. GRB 250704B / EP250704a: 1.3 GHz MeerKAT Detection
  37. GRB 250702B,D,E / EP250702a: 10 GHz detection with the VLA
  38. IPN triangulation of GRB 250704B (short/hard, consistent with EP 250704a)
  39. EP/WXT 01709181970: GOTO observations confirm stellar variability
  40. EP-WXT trigger 01709181970. confirmation of a stellar flare by BOOTES-6
  41. The EP-WXT trigger 01709181970 is likely a flaring star
  42. GRB 250704B / EP250704a: VLA radio detection
  43. GRB 250706B/C: Konus-Wind analysis of the prompt emission
  44. GRB 250704B: CALET Gamma-Ray Burst Monitor detection
  45. IceCube-250706A: EP-FXT follow-up observations
  46. EP250702a/ GRB 250702B: NuSTAR X-ray Observations
  47. EP250706a/GRB 250706A: EP-WXT detection of a fast X-ray transient
  48. The EP-WXT trigger 01709181580 is likely a flaring star
  49. EP250704a / GRB 250704B: end of optical plateau phase and rapid fading of the counterpart
  50. EP250702a/GRB 250702B,C,D,E: Archival radio observations from ASKAP VAST
  51. Radio observation of GRBs 250702B,C,E / EP250702a with the Allen Telescope Array
  52. GRB 250704B: Insight-HXMT detection
  53. Konus-Wind detection of GRB 250703A
  54. EP250704a/GRB 250704B: GSP observations of the optical counterpart
  55. Konus-Wind detection of short/hard GRB 250704B/ EP250704a
  56. EP250704a / GRB 250704B: NOT observations of the optical afterglow
  57. GRB250702F: afterglow detected by joint EP-ZTF shadowing program
  58. EP250704a / GRB 250704B: VLT/X-shooter spectroscopic redshift z = 0.661
  59. EP250704a / GRB 250704B: JinShan optical observations
  60. EP250704a / GRB 250704B : GROWTH-India Telescope optical observations
  61. EP250704a / GRB 250704B: SVOM/VT optical blue counterpart
  62. EP 250704a: BOOTES-5 optical detection
  63. EP250704a: refined analysis of the EP-WXT and FXT follow-up observations
  64. GRBs 250702B/C/D/E / EP250702a: Swift/UVOT Upper Limits
  65. EP250704a / GRB250704B: Swift-XRT counterpart detection
  66. Konus-Wind detection of GRB 250702F
  67. EP250704a / GRB 250704B: VLT/FORS2 optical afterglow detection
  68. EP250704a: COLIBRÍ optical counterpart candidate
  69. EP250704a: Einstein Probe detection of an X-ray transient
  70. GRBs 250702B,C,D,E / EP250702a: SVOM/GRM observation
  71. GRB 250702B,C,D,E/EP250702a: COLIBRÍ optical upper limit
  72. EP250702a/GRB 250702B, C, D, E: EP-FXT follow-up observation
  73. EP250702a: Global MASTER-Net observations report
  74. GRB 250702B,C,D,E / EP 250702a: MAXI/GSC detection
  75. EP250702a/GRB 250702B,C,D,E: GOTO optical upper limits
  76. EP250702a : an X-ray transient detected by Einstein Probe likely associated with GRB 250702B,C,D,E
  77. Konus-Wind detection of GRB 250627A
  78. GRB 250628B: Swift-XRT observations
  79. GRB 250628B: SVOM/VT optical upper limit
  80. GRB 250628B: EP-FXT counterpart detection
  81. The EP-WXT trigger 01709179435 is likely a new outburst of the CV SS Cyg
  82. The EP-WXT trigger 01709179396 is likely a flaring star CSTAR 38580
  83. Konus-Wind detection of GRB 250620C
  84. The EP-WXT trigger 01709179071 is likely a flaring star
  85. EP-WXT trigger 01709179036: a new outburst of GRS 1739-278
  86. The EP-WXT trigger 01709178990 is likely a flaring star
  87. EP#01709178975: Swift-XRT counterpart detection
  88. EP-WXT trigger 01709178975: GOTO optical upper limit
  89. The EP-WXT trigger 01709178975 is likely a flaring star
  90. Konus-Wind detection of GRB 250615A / EP250615a
  91. Konus-Wind detection of GRB 250612C (short/hard with extended emission)
  92. EP250615a/GRB 250615A: EP-WXT detection of a fast X-ray transient
  93. EP-WXT trigger 01709178875: confirmation of a stellar flare by BOOTES-6
  94. The EP-WXT trigger 01709178875 is likely a flaring star
  95. sb25061207: Mephisto optical upper limits
  96. EP250612a / GRB 250612B: NOT optical observations of the afterglow candidate
  97. sb25061207: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  98. EP250612a: refined analysis of the EP-WXT and EP-FXT observations
  99. sb25061207: EP-FXT follow-up observation and afterglow candidate
  100. GRB 250612B: Fermi GBM Observation

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