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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"

28240 results found.

  1. GRB 250424A: Swift-BAT refined analysis
  2. GRB 250424A: SVOM/GRM observation of a long burst
  3. GRB 250424A: PRIME near-infrared detection
  4. GRB 250424A: WINTER J-band detection
  5. GRB 250424A: EIRSAT-1 GMOD Detection
  6. IceCube-250416A: Upper limits from a search for additional neutrino events in IceCube
  7. IceCube-250421A: Upper limits from a search for additional neutrino events in IceCube
  8. GRB 250419A: Mondy Optical Observations
  9. GRB 250424A: Swift/UVOT Detection
  10. Fermi-LAT gamma-ray observations of IceCube-250421A
  11. GRB 250424A: Skynet Optical Observations
  12. GRB 250424A: Kilonova-Catcher optical afterglow detection
  13. GRB 250330B: GRBAlpha detection
  14. GRB 250424A: Swift-XRT refined Analysis
  15. GRB 250424A: Enhanced Swift-XRT position
  16. GRB 250424A: AstroSat CZTI detection of a bright long burst
  17. GRB 250424A: COLIBRÍ Detection of a Bright Optical Counterpart
  18. GRB 250424A: BlackGEM optical afterglow detection
  19. GRB 250424A: DDOTI Afterglow Detection
  20. GRB 250424A: REM optical/NIR afterglow detection
  21. GRB 250424A: Swift detection of a burst with an optical counterpart
  22. Swift GRB 250424A: Global MASTER-Net OT detection
  23. LIGO/Virgo/KAGRA S250328ae: Subaru/PFS Spectroscopic Follow up and Candidates
  24. EP250421a: Nickel optical upper limit
  25. EP250421a: Upper limits from Fermi-GBM Observations
  26. SVOM/sb25042207: SVOM detection of an X-ray transient
  27. IceCube-250421A: DDOTI Detection of the LAST Candidate
  28. GRB 250419A: Mephisto Multi-band Optical Detection
  29. GRB 250419A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  30. IC-250421A: LAST optical observations of the IceCube neutrino candidate
  31. EP250421a: NOT optical observations
  32. GRB 250419A: Optical Observations via Virtual Telescope Project
  33. EP250421a: REM optical upper limit
  34. EP250421A: COLIBRÍ Optical Upper Limit
  35. GRB 250419A: Mondy Continued Optical Observations
  36. GRB 250421B: AstroSat CZTI detection of a bright long burst
  37. EP250421a: Einstein Probe detection of an X-ray transient
  38. EP250421a: Mephisto optical counterpart confirmation
  39. IceCube-Cascade 250414A: Upper limits from a search for additional neutrino events in IceCube
  40. EP250421a: JinShan likely optical counterpart
  41. The EP-WXT trigger 01709135179: Kinder optical counterpart candidate
  42. GRB 250419A: LCO optical observation
  43. GRB 250419A: JinShan optical observations
  44. GRB 250419A: SVOM/C-GFT optical observations
  45. GRB 250419A: Swift/UVOT Follow up
  46. GRB 250416C / EP250416a: SVOM/GRM observation of a burst
  47. GRB 250419A: LCO optical afterglow multi-band observations
  48. GRB 250419A: Mondy and AbAO Optical Observations
  49. GRB 250419A: AKO Optical Afterglow Detection
  50. Fermi-LAT Gamma-ray Observations of IceCube-250416A
  51. GRB 250419A: Swift-XRT refined Analysis
  52. GRB 250419A: KAIT optical afterglow observations
  53. GRB 250419A: SVOM/VT optical bright counterpart confirmation
  54. GRB 250419A: SVOM/COLIBRÍ (FM-GFT) Detection of the Optical Counterpart
  55. GRB 250419A: SVOM detection of a soft burst
  56. EP250416a: Swift/XRT counterpart fading
  57. EP20250416a: Swift/XRT counterpart detection
  58. IceCube-250416A: DDOTI Optical Observations
  59. EP250416a: Gemini South-GMOS optical counterpart
  60. SVOM/sb25041603 is not a GRB
  61. EP250416a: GSP optical upper limit
  62. EP250416a: Einstein Probe detection of an X-ray transient
  63. SVOM/sb25041603: SVOM/COLIBRÍ (FM-GFT) Upper Limit on the Optical Counterpart
  64. SVOM/sb25041603: SVOM detection of an X-ray transient
  65. IceCube 250414.324: DDOTI Optical Observations
  66. GRB 250413A: AstroSat CZTI detection
  67. EP250304a: ATCA radio observations
  68. EP250404a: Nanshan 0.43m Telescope optical observatios
  69. GRB 250411A: DDOTI Optical Observations
  70. Fermi GRB 250411A: Global MASTER-Net observations report
  71. GRB 250407A: Continued KAIT/Nickel optical observations
  72. GRB 250314A: e-MERLIN observations
  73. GRB 250407A: Mondy and AbAO Optical Observations
  74. EP250227a: Further NOT optical observations
  75. GRB 250320B: cubesat Avion detection
  76. IceCube-250406A: Swift-XRT observations
  77. GRB 250407A: LCO detection of a fading optical counterpart
  78. Fermi-LAT gamma-ray observations of IceCube-250406A
  79. IceCube-250406A: Upper limits from a search for additional neutrino events in IceCube
  80. GRB 250407A: SVOM/GRM observation of a bright long burst
  81. GRB 250407A: EP-WXT afterglow detection
  82. EP250407a: EP-WXT detection of a fast X-ray transient
  83. GRB 250407A: COLIBRÍ/DDRAGO Detection of the Optical Counterpart
  84. GRB 250407A: KAIT Optical Afterglow Candidate
  85. IceCube-250406A: No candidates from the Zwicky Transient Facility
  86. GRB 250407A: Fermi GBM Detection
  87. GRB 250407A: Swift-XRT afterglow detection
  88. GRB 250407A: SRG/ART-XC afterglow detection
  89. LIGO/Virgo/KAGRA S250331o: Upper limits from Swift/BAT-GUANO
  90. IceCube 250406A: DDOTI Optical Observations of the Refined Position
  91. IPN triangulation of GRB 250406B (short/hard)
  92. GRB 250407A: BALROG localization (Fermi Trigger 765733706 / GRB 250407659)
  93. IceCube 250406.951: COLIBRÍ/DDRAGO Optical Upper Limit
  94. IceCube 250406.951: DDOTI Optical Observations
  95. GRB 250406A: AstroSat CZTI detection
  96. EP250404a: Multi-band Optical Observations from UCAS-70 and XL-C14
  97. GRB 250404A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  98. EP250404a / GRB 250404A: Montarrenti Observatory optical observations
  99. GRB 250404A / EP250404a: SVOM/GWAC-F60 and F50 observations
  100. EP250404a / GRB 250404A: J band observations by SYSU 80cm telescope

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