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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"

12172 results found.

  1. GRB 250509A: Swift detection of a burst
  2. EP250508a: refined analysis of the EP-WXT and EP-FXT observations
  3. GRB 250506A: Swift-XRT afterglow detection
  4. EP250508a: Global MASTER-Net observations report
  5. EP250508a: Einstein Probe detection of an X-ray transient
  6. GRB 250507A: refined SVOM/MXT data analysis
  7. Fermi-LAT Gamma-ray Observations of IceCube-250506A
  8. IceCube Alert 250506.59: Global MASTER-Net observations report
  9. GRB 250430A: Konus-Wind detection and joint Konus-Wind+Swift-BAT spectral analysis
  10. GRB 250506A: REM optical/NIR upper limits
  11. GRB 250506A: Fermi GBM Observation
  12. GRB 250504A: Swift-BAT refined analysis
  13. GRB 250504A: REM optical/NIR observations
  14. GRB 250504A: MeerLICHT optical afterglow detection
  15. Fermi GRB 250504A: Global MASTER-Net observations report
  16. GRB 250504A: Swift detection of a burst
  17. GRB 250502A: Mondy and Tien-Shan Optical Observations
  18. GRB 250502A: Montarrenti Observatory optical detection
  19. GRB 250502A: Swift-XRT afterglow detection
  20. GRB 250502B: AstroSat CZTI detection
  21. GRB 250502A: LCO optical counterpart detection
  22. GRB 250502C: Fermi GBM Final Localization
  23. GRB 250407A: VZLUSAT-2 detection
  24. Fermi-LAT Gamma-ray Observations of IceCube-250429A
  25. GRB 250502B: DDOTI Optical Observations
  26. GRB 250430A: Swift-XRT refined Analysis
  27. GRB 250430A: Swift/UVOT Detection
  28. Fermi GRB 250502B: Global MASTER-Net observations report
  29. GRB 250430A: Swift detection of a burst with optical counterpart
  30. EP250428b: refined analysis of the EP-FXT follow-up observation
  31. EP250428b: SAO RAS optical upper limit
  32. EP250428b: Einstein Probe detection of a fast X-ray transient
  33. Fermi-LAT Gamma-ray Observations of IceCube-250426A
  34. EP250427a: REM optical/NIR afterglow detection
  35. EP250427a: Einstein Probe detection of a fast X-ray transient
  36. IceCube Alert 250426.74: Global MASTER-Net observations report
  37. IceCube-250421A: Upper limits from a search for additional neutrino events in IceCube
  38. Konus-Wind detection of GRB 250424A
  39. Fermi-LAT gamma-ray observations of IceCube-250421A
  40. GRB 250424A: Kilonova-Catcher optical afterglow detection
  41. GRB 250404A / EP250404a: GRBAlpha detection
  42. GRB 250424A: Swift-XRT refined Analysis
  43. GRB 250424A: AstroSat CZTI detection of a bright long burst
  44. GRB 250424A: DDOTI Afterglow Detection
  45. LIGO/Virgo/KAGRA S250328ae: Subaru/PFS Spectroscopic Follow up and Candidates
  46. SVOM/sb25042207: BOOTES-2 early optical upper limit
  47. SVOM/sb25042207: GOTO optical upper limits
  48. GRB 250421A: AstroSat CZTI detection
  49. GRB 250419A: Mephisto Multi-band Optical Detection
  50. GRB 250419A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  51. IC-250421A: LAST optical observations of the IceCube neutrino candidate
  52. GRB 250419A: Mondy Continued Optical Observations
  53. Fermi GRB 250421A: Global MASTER-Net observations report
  54. GRB 250421B: AstroSat CZTI detection of a bright long burst
  55. IceCube Alert 250421.71: Global MASTER-Net observations report
  56. GRB 250419A: Liverpool Telescope observations
  57. GRB 250419A: JinShan optical observations
  58. GRB 250416C / EP250416a: SVOM/GRM observation of a burst
  59. GRB 250419A: LCO optical afterglow multi-band observations
  60. GRB 250419A: MASTER optical afterglow observation
  61. Fermi-LAT Gamma-ray Observations of IceCube-250416A
  62. GRB 250419A: Swift-XRT refined Analysis
  63. Konus-Wind detection of GRB 250416C (a counterpart of EP250416a)
  64. EP250416a: refined EP-WXT and EP-FXT analysis
  65. Konus-Wind detection of GRB 250403A
  66. IceCube-250416A: DDOTI Optical Observations
  67. EP250416a: GSP optical upper limit
  68. EP250416a: Global MASTER-Net observations report
  69. EP250416a: Einstein Probe detection of an X-ray transient
  70. IceCube-250416A: Global MASTER-Net observations report
  71. GRB 250413A: AstroSat CZTI detection
  72. GRB 250412A: AstroSat CZTI detection
  73. EP250404a: Nanshan 0.43m Telescope optical observatios
  74. Fermi trigger No 766148493: Global MASTER-Net observations report
  75. Fermi trigger No 766173972: Global MASTER-Net observations report
  76. Fermi GRB 250411A: Global MASTER-Net observations report
  77. GRB 250320B: cubesat Avion detection
  78. Fermi-LAT gamma-ray observations of IceCube-250406A
  79. Konus-Wind detection of GRB 250407A
  80. GRB 250407A: EP-WXT afterglow detection
  81. GRB 250407A: COLIBRÍ/DDRAGO Detection of the Optical Counterpart
  82. GRB 250407A: Fermi GBM Detection
  83. GRB 250407A: Swift-XRT afterglow detection
  84. Fermi GRB 250407A: Global MASTER-Net observations report
  85. GRB 250407A: SRG/ART-XC afterglow detection
  86. LIGO/Virgo/KAGRA S250331o: Upper limits from Swift/BAT-GUANO
  87. Konus-Wind detection of GRB 250406B (short/hard)
  88. GRB 250406A: AstroSat CZTI detection
  89. Fermi trigger No 765663719: Global MASTER-Net observations report
  90. Fermi GRB 250406A: Global MASTER-Net observations report
  91. EP250404a / GRB 250404A: Montarrenti Observatory optical observations
  92. EP250404a / GRB 250404A: J band observations by SYSU 80cm telescope
  93. Konus-Wind detection of GRB 250404A / EP250404a
  94. EP250404a: refined analysis of the EP-WXT and EP-FXT observations
  95. GRB 250404A / EP250404a: Leavitt Observatory optical counterpart detection
  96. GRB 250404B: AstroSat CZTI detection of a short burst
  97. GRB 250403A: AstroSat CZTI detection
  98. EP250404a: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  99. EP250404a: LCO optical counterpart detection
  100. Fermi GRB 250404A: Global MASTER-Net observations report

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