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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"

28302 results found.

  1. EP250421a: Einstein Probe detection of an X-ray transient
  2. EP250421a: Mephisto optical counterpart confirmation
  3. IceCube-Cascade 250414A: Upper limits from a search for additional neutrino events in IceCube
  4. EP250421a: JinShan likely optical counterpart
  5. The EP-WXT trigger 01709135179: Kinder optical counterpart candidate
  6. GRB 250419A: LCO optical observation
  7. GRB 250419A: JinShan optical observations
  8. GRB 250419A: SVOM/C-GFT optical observations
  9. GRB 250419A: Swift/UVOT Follow up
  10. GRB 250416C / EP250416a: SVOM/GRM observation of a burst
  11. GRB 250419A: LCO optical afterglow multi-band observations
  12. GRB 250419A: Mondy and AbAO Optical Observations
  13. GRB 250419A: AKO Optical Afterglow Detection
  14. Fermi-LAT Gamma-ray Observations of IceCube-250416A
  15. GRB 250419A: Swift-XRT refined Analysis
  16. GRB 250419A: KAIT optical afterglow observations
  17. GRB 250419A: SVOM/VT optical bright counterpart confirmation
  18. GRB 250419A: SVOM/COLIBRÍ (FM-GFT) Detection of the Optical Counterpart
  19. GRB 250419A: SVOM detection of a soft burst
  20. EP250416a: Swift/XRT counterpart fading
  21. EP20250416a: Swift/XRT counterpart detection
  22. IceCube-250416A: DDOTI Optical Observations
  23. EP250416a: Gemini South-GMOS optical counterpart
  24. SVOM/sb25041603 is not a GRB
  25. EP250416a: GSP optical upper limit
  26. EP250416a: Einstein Probe detection of an X-ray transient
  27. SVOM/sb25041603: SVOM/COLIBRÍ (FM-GFT) Upper Limit on the Optical Counterpart
  28. SVOM/sb25041603: SVOM detection of an X-ray transient
  29. IceCube 250414.324: DDOTI Optical Observations
  30. GRB 250413A: AstroSat CZTI detection
  31. EP250304a: ATCA radio observations
  32. EP250404a: Nanshan 0.43m Telescope optical observatios
  33. GRB 250411A: DDOTI Optical Observations
  34. Fermi GRB 250411A: Global MASTER-Net observations report
  35. GRB 250407A: Continued KAIT/Nickel optical observations
  36. GRB 250314A: e-MERLIN observations
  37. GRB 250407A: Mondy and AbAO Optical Observations
  38. EP250227a: Further NOT optical observations
  39. GRB 250320B: cubesat Avion detection
  40. IceCube-250406A: Swift-XRT observations
  41. GRB 250407A: LCO detection of a fading optical counterpart
  42. Fermi-LAT gamma-ray observations of IceCube-250406A
  43. IceCube-250406A: Upper limits from a search for additional neutrino events in IceCube
  44. GRB 250407A: SVOM/GRM observation of a bright long burst
  45. GRB 250407A: EP-WXT afterglow detection
  46. EP250407a: EP-WXT detection of a fast X-ray transient
  47. GRB 250407A: COLIBRÍ/DDRAGO Detection of the Optical Counterpart
  48. GRB 250407A: KAIT Optical Afterglow Candidate
  49. IceCube-250406A: No candidates from the Zwicky Transient Facility
  50. GRB 250407A: Fermi GBM Detection
  51. GRB 250407A: Swift-XRT afterglow detection
  52. GRB 250407A: SRG/ART-XC afterglow detection
  53. LIGO/Virgo/KAGRA S250331o: Upper limits from Swift/BAT-GUANO
  54. IceCube 250406A: DDOTI Optical Observations of the Refined Position
  55. IPN triangulation of GRB 250406B (short/hard)
  56. GRB 250407A: BALROG localization (Fermi Trigger 765733706 / GRB 250407659)
  57. IceCube 250406.951: COLIBRÍ/DDRAGO Optical Upper Limit
  58. IceCube 250406.951: DDOTI Optical Observations
  59. GRB 250406A: AstroSat CZTI detection
  60. EP250404a: Multi-band Optical Observations from UCAS-70 and XL-C14
  61. GRB 250404A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  62. EP250404a / GRB 250404A: Montarrenti Observatory optical observations
  63. GRB 250404A / EP250404a: SVOM/GWAC-F60 and F50 observations
  64. EP250404a / GRB 250404A: J band observations by SYSU 80cm telescope
  65. Konus-Wind detection of GRB 250404A / EP250404a
  66. EP250404a: refined analysis of the EP-WXT and EP-FXT observations
  67. GRB 250404A / EP250404a: Leavitt Observatory optical counterpart detection
  68. GRB 250402A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  69. EP250402a: Optical upper limit with PD 1.3m observations
  70. GRB 250404A / EP250404a: NOT optical observations
  71. GRB 250331D: Swift-XRT afterglow detection
  72. GRB 250404B: AstroSat CZTI detection of a short burst
  73. EP250404a: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  74. EP250404a: REM optical/NIR observations
  75. EP250404a: Seimei/TriCCS optical counterpart detection
  76. EP250404A: COLIBRÍ/DDRAGO Optical Observations
  77. EP250404A / GRB250404A: Ondrejov D50 optical afterglow detection
  78. EP250404a: LCO optical counterpart detection
  79. EP250404a: Xinglong decaying optical counterpart
  80. GRB 250403A: Montarrenti Observatory optical detection
  81. GRB 250404A: Fermi GBM Detection
  82. GRB 250403A: KAIT optical observations
  83. EP250404a: AKO Optical Afterglow Detection
  84. EP250404a: LAST detection of optical counterpart
  85. GRB 250402A: Swift/BAT-GUANO localization skymap of a burst
  86. GRB 250403A: Fermi GBM observations
  87. GRB 250327B: VIRT Optical Upper Limit
  88. EP250404a: Mephisto multi-band optical detection
  89. GRB 250331C Swift-BAT refined analysis
  90. GRB 250331B Swift-BAT refined analysis
  91. GRB 250330A Swift-BAT refined analysis
  92. EP250321A: J band upper limit by SYSU 80cm telescope
  93. EP250404a: Nanshan/HMT optical counterpart detection
  94. EP250404a: Einstein Probe detection of an X-ray transient
  95. GRB 250403A: Swift/UVOT Detection
  96. GRB 250402A: Swift/UVOT Upper Limits
  97. EP250402a: Optical upper limit with Kinder observations
  98. GRB 250403A: REM NIR afterglow detection
  99. GRB 250403A: LCO optical counterpart detection
  100. IceCube-250330A: MASTER detection of PKS 2032+107 blazar flare with Zhirkov effect

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