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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"

12170 results found.

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

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