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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').
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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"

28108 results found.

  1. IC-250421A: LAST optical observations of the IceCube neutrino candidate
  2. EP250421a: NOT optical observations
  3. GRB 250419A: Optical Observations via Virtual Telescope Project
  4. EP250421a: REM optical upper limit
  5. EP250421A: COLIBRÍ Optical Upper Limit
  6. GRB 250419A: Mondy Continued Optical Observations
  7. GRB 250421B: AstroSat CZTI detection of a bright long burst
  8. EP250421a: Einstein Probe detection of an X-ray transient
  9. EP250421a: Mephisto optical counterpart confirmation
  10. IceCube-Cascade 250414A: Upper limits from a search for additional neutrino events in IceCube
  11. EP250421a: JinShan likely optical counterpart
  12. The EP-WXT trigger 01709135179: Kinder optical counterpart candidate
  13. GRB 250419A: LCO optical observation
  14. GRB 250419A: JinShan optical observations
  15. GRB 250419A: SVOM/C-GFT optical observations
  16. GRB 250419A: Swift/UVOT Follow up
  17. GRB 250416C / EP250416a: SVOM/GRM observation of a burst
  18. GRB 250419A: LCO optical afterglow multi-band observations
  19. GRB 250419A: Mondy and AbAO Optical Observations
  20. GRB 250419A: AKO Optical Afterglow Detection
  21. Fermi-LAT Gamma-ray Observations of IceCube-250416A
  22. GRB 250419A: Swift-XRT refined Analysis
  23. GRB 250419A: KAIT optical afterglow observations
  24. GRB 250419A: SVOM/VT optical bright counterpart confirmation
  25. GRB 250419A: SVOM/COLIBRÍ (FM-GFT) Detection of the Optical Counterpart
  26. GRB 250419A: SVOM detection of a soft burst
  27. EP250416a: Swift/XRT counterpart fading
  28. EP20250416a: Swift/XRT counterpart detection
  29. IceCube-250416A: DDOTI Optical Observations
  30. EP250416a: Gemini South-GMOS optical counterpart
  31. SVOM/sb25041603 is not a GRB
  32. EP250416a: GSP optical upper limit
  33. EP250416a: Einstein Probe detection of an X-ray transient
  34. SVOM/sb25041603: SVOM/COLIBRÍ (FM-GFT) Upper Limit on the Optical Counterpart
  35. SVOM/sb25041603: SVOM detection of an X-ray transient
  36. IceCube 250414.324: DDOTI Optical Observations
  37. GRB 250413A: AstroSat CZTI detection
  38. EP250304a: ATCA radio observations
  39. EP250404a: Nanshan 0.43m Telescope optical observatios
  40. GRB 250411A: DDOTI Optical Observations
  41. Fermi GRB 250411A: Global MASTER-Net observations report
  42. GRB 250407A: Continued KAIT/Nickel optical observations
  43. GRB 250314A: e-MERLIN observations
  44. GRB 250407A: Mondy and AbAO Optical Observations
  45. EP250227a: Further NOT optical observations
  46. GRB 250320B: cubesat Avion detection
  47. IceCube-250406A: Swift-XRT observations
  48. GRB 250407A: LCO detection of a fading optical counterpart
  49. Fermi-LAT gamma-ray observations of IceCube-250406A
  50. IceCube-250406A: Upper limits from a search for additional neutrino events in IceCube
  51. GRB 250407A: SVOM/GRM observation of a bright long burst
  52. GRB 250407A: EP-WXT afterglow detection
  53. EP250407a: EP-WXT detection of a fast X-ray transient
  54. GRB 250407A: COLIBRÍ/DDRAGO Detection of the Optical Counterpart
  55. GRB 250407A: KAIT Optical Afterglow Candidate
  56. IceCube-250406A: No candidates from the Zwicky Transient Facility
  57. GRB 250407A: Fermi GBM Detection
  58. GRB 250407A: Swift-XRT afterglow detection
  59. GRB 250407A: SRG/ART-XC afterglow detection
  60. LIGO/Virgo/KAGRA S250331o: Upper limits from Swift/BAT-GUANO
  61. IceCube 250406A: DDOTI Optical Observations of the Refined Position
  62. IPN triangulation of GRB 250406B (short/hard)
  63. GRB 250407A: BALROG localization (Fermi Trigger 765733706 / GRB 250407659)
  64. IceCube 250406.951: COLIBRÍ/DDRAGO Optical Upper Limit
  65. IceCube 250406.951: DDOTI Optical Observations
  66. GRB 250406A: AstroSat CZTI detection
  67. EP250404a: Multi-band Optical Observations from UCAS-70 and XL-C14
  68. GRB 250404A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  69. EP250404a / GRB 250404A: Montarrenti Observatory optical observations
  70. GRB 250404A / EP250404a: SVOM/GWAC-F60 and F50 observations
  71. EP250404a / GRB 250404A: J band observations by SYSU 80cm telescope
  72. Konus-Wind detection of GRB 250404A / EP250404a
  73. EP250404a: refined analysis of the EP-WXT and EP-FXT observations
  74. GRB 250404A / EP250404a: Leavitt Observatory optical counterpart detection
  75. GRB 250402A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  76. EP250402a: Optical upper limit with PD 1.3m observations
  77. GRB 250404A / EP250404a: NOT optical observations
  78. GRB 250331D: Swift-XRT afterglow detection
  79. GRB 250404B: AstroSat CZTI detection of a short burst
  80. EP250404a: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  81. EP250404a: REM optical/NIR observations
  82. EP250404a: Seimei/TriCCS optical counterpart detection
  83. EP250404A: COLIBRÍ/DDRAGO Optical Observations
  84. EP250404A / GRB250404A: Ondrejov D50 optical afterglow detection
  85. EP250404a: LCO optical counterpart detection
  86. EP250404a: Xinglong decaying optical counterpart
  87. GRB 250403A: Montarrenti Observatory optical detection
  88. GRB 250404A: Fermi GBM Detection
  89. GRB 250403A: KAIT optical observations
  90. EP250404a: AKO Optical Afterglow Detection
  91. EP250404a: LAST detection of optical counterpart
  92. GRB 250402A: Swift/BAT-GUANO localization skymap of a burst
  93. GRB 250403A: Fermi GBM observations
  94. GRB 250327B: VIRT Optical Upper Limit
  95. EP250404a: Mephisto multi-band optical detection
  96. GRB 250331C Swift-BAT refined analysis
  97. GRB 250331B Swift-BAT refined analysis
  98. GRB 250330A Swift-BAT refined analysis
  99. EP250321A: J band upper limit by SYSU 80cm telescope
  100. EP250404a: Nanshan/HMT optical counterpart detection

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