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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"

28107 results found.

  1. GRB 250704A: Swift-XRT afterglow detection
  2. GRB 250702B / EP2050702a: FTW optical and NIR observations
  3. Konus-Wind detection of GRB 250702F
  4. EP250704a / GRB 250704B - REM observations
  5. GRB 250702F: GROWTH-India Telescope optical observations
  6. EP250704a / GRB 250704B: VLT/FORS2 optical afterglow detection
  7. GRB 250704A: REM retraction of optical afterglow detection and updated limit
  8. EP250702a: WFST optical observations
  9. EP250704a: Einstein Probe detection of an X-ray transient
  10. GRB 250702F: optical photometry from Konkoly
  11. GRB 250704A: REM detection of the optical afterglow
  12. GRB 250702F: SVOM/VT optical observation
  13. GRB 250704A: SVOM detection of a burst
  14. GRB 250702F: Swift/UVOT Detection
  15. GRB 250702A: CALET Gamma-Ray Burst Monitor detection
  16. GRBs 250702B,C,D,E / EP250702a: 2.2m CAHA optical upper limit
  17. GRB 250702F: Swift-XRT refined Analysis
  18. GRB 250702F: Leavitt Observatory optical observations
  19. GRB 250702F: AKO Optical Afterglow Detection
  20. GRBs 250702B,C,D,E / EP250702a: VLT/HAWK-I NIR candidate
  21. GRB 250702A: GECAM-B detection
  22. GRB 250702F: Skynet Optical Observations
  23. GRB 250424A: VIRT Optical Upper Limit
  24. GRBs 250702B/C/D/E / EP250702a: Swift XRT localization
  25. EP250702a/GRB 250702B, C, D, E: EP-FXT follow-up observation
  26. GRB 250702F: TRT Optical Observation
  27. GRBs 250702B,C,D,E / EP250702a: Konus-Wind detection of a hard X-ray transient activity
  28. GRB 250702F: REM optical afterglow detection
  29. GRB 250702B,C,D,E / EP 250702a: MAXI/GSC detection
  30. GRB 250703A: Fermi GBM Final Real-time Localization
  31. GRB 250702F: COLIBRÍ Observations of the Afterglow
  32. EP250702a : an X-ray transient detected by Einstein Probe likely associated with GRB 250702B,C,D,E
  33. GRB 250702F: Enhanced Swift-XRT position
  34. GRB 250702F: GTC/OSIRIS+ spectroscopic redshift z = 1.520
  35. GRB 250702F: NOT observations of the optical afterglow
  36. GRB 250702F: MASTER optical afterglow observation
  37. GRB 250702F: GOTO optical counterpart detection
  38. GRB 250702F: Ondrejov D50 optical afterglow detection
  39. GRB 250702F: Swift detection of a burst with an optical counterpart
  40. GRB 250702F: Fermi GBM Final Real-time Localization
  41. GRB 250702E: Fermi GBM Final Real-time Localization
  42. Konus-Wind detection of GRB 250627A
  43. IPN triangulation of GRB 250627A (short)
  44. GRB 250702A: Fermi GBM Detection
  45. GRB 250702D: Fermi GBM Final Localization Correction
  46. GRB 250702C: Fermi GBM Final Real-time Localization
  47. GRB 250702B: Fermi GBM Final Real-time Localization
  48. GRB 250702A: Fermi GBM Final Real-time Localization
  49. GRB 250628B: Swift-XRT observations
  50. GRB 250628B: SVOM/VT optical upper limit
  51. GRB 250628B: EP-FXT counterpart detection
  52. GRB 250627A: Insight-HXMT detection
  53. GRB 250627A: SVOM/GRM detection of a short burst
  54. GRB 250628A: REM optical/NIR upper limits
  55. GRB 250628C: Fermi GBM Final Real-time Localization
  56. GRB 250628B: SVOM detection of a long burst
  57. GRB 250625A: VLT/X-shooter spectroscopic observations at the afterglow position
  58. GRB 250628A: VLT/X-shooter upper limits
  59. GRB 250628A: Swift/UVOT Upper Limits
  60. GRB 250628A: Swift-XRT refined Analysis
  61. GRB 250628A: Enhanced Swift-XRT position
  62. GRB 250628A: Swift detection of a burst
  63. GRB 250625A: Leavitt Observatory afterglow detection
  64. GRB 250625A: AbAO and INASAN Kislovodsk Optical Observations
  65. GRB 250625A: GTC/OSIRIS+ spectroscopic observations of the potential host galaxy
  66. GRB 250626A: Fermi GBM Final Real-time Localization
  67. GRB 250625A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  68. GRB 250625A: SVOM/C-GFT upper limit in early phase
  69. GRB 250625A: GECAM-B detection
  70. GRB 250625A: Swift/UVOT Upper Limits
  71. GRB 250625A: ABObservatory afterglow detection
  72. GRB 250625A: OHP/T193 optical detection
  73. GRB 250625A: COLIBRÍ optical observations
  74. GRB 250625A: Fermi-LAT detection
  75. GRB 250625A: Swift-XRT refined Analysis
  76. GRB 250625A: JinShan optical observations
  77. GRB250625A: Fermi GBM Observation
  78. GRB 250625A: NOT z-band upper limit
  79. GRB 250625A: SVOM/VT optical confirmation
  80. GRB 250625A: SAO RAS possible optical afterglow
  81. GRB 250625A: Enhanced Swift-XRT position
  82. GRB 250625A: Swift detection of a burst
  83. GRB 250625A: Fermi GBM Final Real-time Localization
  84. GRB 250620A: AstroSat CZTI detection
  85. GRB 241018A: Maidanak optical observations
  86. GRB 250620C: AstroSat CZTI detection
  87. GRB 250624A: Fermi GBM Final Real-time Localization
  88. sb25061207/GRB 250612D - SVOM/ECLAIRs refined analysis
  89. GRB 250623A: Fermi GBM Final Real-time Localization
  90. GRB 250521A: VZLUSAT-2 detection
  91. Konus-Wind detection of GRB 250620C
  92. IPN triangulation of GRB 250620C (long/bright)
  93. GRB 250621B: SVOM/GRM detection of a possible magnetar X-ray burst
  94. GRB 250617B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  95. GRB 250621A: Fermi GBM Final Real-time Localization
  96. GRB 250620A: Swift/BAT-GUANO subthreshold detection of a possibly short burst
  97. GRB 250620C: Fermi GBM Final Real-time Localization
  98. GRB 250620B: Fermi GBM Final Real-time Localization
  99. GRB 250620A: Fermi GBM Final Real-time Localization
  100. EP-WXT trigger 01709179036: a new outburst of GRS 1739-278

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