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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"

35996 results found.

  1. GRB 250209A: MAXI/GSC detection (possible detection of an X-ray flare from 1RXS J145110.3+310648)
  2. Fermi GRB 250210A: Global MASTER-Net observations report
  3. GRB 250210A: Fermi GBM Final Real-time Localization
  4. LIGO/Virgo/KAGRA S250206dm: Upper limits from GECAM Observations
  5. GRB 250204B: GRBAlpha detection
  6. GRB 250204A: GRBAlpha detection
  7. GRB 250207A: 1.3m DFOT Optical observations
  8. GRB 250206A: Swift-XRT observations
  9. GRB 250129A: GRANDMA Continued Afterglow Detection
  10. GRB 250207A: Swift-BAT refined analysis
  11. GRB 250205A: 1.3m DFOT optical upper limit
  12. GRB 250206A: Tiled Swift observations
  13. GRB 250206A: EIRSAT-1 GMOD Detection
  14. GRB 250206A: Fermi-LAT detection
  15. GRB 250207B: Swift-XRT observations
  16. GRB 250208A: Fermi GBM Final Real-time Localization
  17. GRB 250207A: Swift-XRT refined Analysis
  18. GRB 250207A: Enhanced Swift-XRT position
  19. GRB 250129A: ABObservatory SLOAN r’ afterglow detection
  20. GRB 250207A: REM IR afterglow detection
  21. GRB 250207A: FRAM-Auger optical detection
  22. GRB 250207B: Tiled Swift observations
  23. Konus-Wind detection of GRB 250204B
  24. GRB 250207A: REM optical afterglow detection
  25. GRB 250207A: Swift/UVOT Detection
  26. LIGO/Virgo/KAGRA S250206dm: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  27. GRB 250129A: Continued AbAO and Mondy optical observations
  28. GRB 250207B: MAXI/GSC detection
  29. GRB 250207A: COLIBRÍ/DDRAGO Optical Afterglow Detection
  30. LIGO/Virgo/KAGRA S250206dm: Upper limits from Fermi-GBM Observations
  31. GRB 250207A: Swift detection of a burst with optical counterpart
  32. GRB 250207A: Fermi GBM Final Real-time Localization
  33. GRB 250206A: BALROG localization (Fermi Trigger 760564296 / GRB 250206827)
  34. GRB 250206A: Fermi GBM Final Real-time Localization
  35. GRB 250205A: Fermi GBM Observation
  36. GRB 250205A: REM NIR upper limit
  37. EP250205a/GRB 250205A: FTW optical and NIR observations of the counterpart
  38. GRB 250205A: Swift/UVOT Upper Limits
  39. EP250205a/GRB 250205A: correction to the source localization
  40. EP250205a/GRB 250205A: Einstein Probe observation
  41. GRB 250127C: SVOM/GRM observation of a burst
  42. GRB 250204B: SVOM/GRM observation of a likely short burst
  43. GRB 250205A: COLIBRÍ/DDRAGO Optical Afterglow Detection
  44. GRB 250205A: Swift/XRT detection
  45. GRB 250205A: Redshift from OSIRIS+/GTC z = 3.55
  46. GRB250205A: SVOM/VT optical afterglow detection
  47. GRB 250205A: GOTO optical upper limits
  48. GRB 250205A: OHP/T193 optical counterpart candidate
  49. GRB 250205A: Liverpool Telescope optical counterpart candidate detection
  50. GRB 250205A: SVOM detection of a burst
  51. Konus-Wind detection of GRB 250201A
  52. IPN triangulation of GRB 250201A
  53. Konus-Wind detection of GRB 250202B
  54. GRB 250129A: Swift-BAT refined analysis
  55. EP 250108A: Upper limits from Fermi-GBM Observations
  56. IPN triangulation of GRB 250204B (short/hard)
  57. IPN triangulation of GRB 250202B
  58. GRB 250204B: AstroSat CZTI detection of a short burst
  59. GRB 250204B: Fermi GBM Final Localization
  60. GRB 250129A: LCO late afterglow detection
  61. GRB 250129A: AbAO AS-32 and Mondy AZT-33IK optical observations
  62. GRB 250204A: Fermi GBM Final Real-time Localization
  63. GRB 250129A: COLIBRÍ/DDRAGO Afterglow Detection
  64. GRB 250202B: NuSTAR detection of the prompt emission
  65. GRB 250202C: GRBAlpha detection
  66. GRB 250202B: Fermi GBM Detection
  67. GRB 250129a: Liverpool Telescope optical follow-up
  68. GRB 240129A: further SAO RAS optical observations
  69. GRB 250129A: 7DT Detection and Medium-band SED of Afterglow
  70. GRB 250202C: Fermi GBM Final Real-time Localization
  71. GRB 250129A: SVOM/C-GFT optical observations
  72. GRB 250202B: AstroSat CZTI detection of a bright long GRB
  73. GRB 250202B: Fermi GBM Final Real-time Localization
  74. Swift GRB250129A: MASTER 4 days observations report
  75. GRB 250202A: Fermi GBM Final Real-time Localization
  76. GRB 250201A: INTEGRAL SPI/ACS detection
  77. Konus-Wind detection of GRB 250129A
  78. GRB 250129A: 1.3m DFOT Optical observations
  79. GRB 250129A: Liverpool Telescope observations suggest continued engine activity
  80. GRB 250201A: BALROG localization (Fermi Trigger 760096791 / GRB 250201417)
  81. GRB 250201A: Fermi GBM Final Real-time Localization
  82. GRB 250129A: Skynet Continued Optical Observations
  83. GRB 250129A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations
  84. GRB 250129A: SAO RAS optical observations
  85. GRB 250129A: COLIBRÍ Continuing Detection of the Afterglow
  86. GRB 250129A: optical photometry from Konkoly
  87. GRB 250129A: COLIBRÍ Optical Observations
  88. GRB 250128B: VLA possible radio detection
  89. GRB 250129A: continued KAIT observations indicating steep decay after 28.5h
  90. GRB 250129A: iTelescope optical observation
  91. GRB 250129A: NOT optical observations of continuining activity
  92. GRB 250129a: Liverpool Telescope optical follow-up
  93. GRB 250129A: TNG NIR afterglow detection
  94. GRB 250129A: AKO Optical Afterglow Detection
  95. GRB 250129A: GRANDMA/TAROT optical afterglow detection
  96. GRB 250127A: EP-FXT second observation epoch and confirmation of the x-ray afterglow fading
  97. GRB 250128B: SAO RAS Zeiss-1000 and CrAO ZTSh optical upper limits
  98. GRB 250128B: VLA radio upper limit
  99. GRB 250129A: Skynet optical observations
  100. GRB 250129A: KAIT optical observations of the rebrightening around 5.1 hours

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