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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"

11662 results found.

  1. GRB 250421A: Fermi GBM Final Real-time Localization
  2. Fermi-LAT Gamma-ray Observations of IceCube-250416A
  3. GRB 250407A: GTC/OSIRIS+ spectroscopic redshift z = 1.36
  4. Konus-Wind detection of GRB 250403A
  5. GRB 250403A: VLT/FORS2 spectroscopic redshift z = 1.847
  6. Fermi Gamma-ray Burst Monitor trigger 766505186/250416588 (GRB 250416A) is not a GRB
  7. IceCube-250416A - IceCube observation of a high-energy neutrino candidate track-like event
  8. Fermi Gamma-ray Burst Monitor trigger 766511207/250416657 is not a GRB
  9. GRB 250416B: Fermi GBM Final Real-time Localization
  10. GRB 250416A: Fermi GBM Final Real-time Localization
  11. Fermi Gamma-ray Burst Monitor trigger 766474855/250416237 is not a GRB
  12. GRB 250412A: AstroSat CZTI detection
  13. Fermi trigger No 766148493: Global MASTER-Net observations report
  14. Fermi trigger No 766173972: Global MASTER-Net observations report
  15. GRB 250411A: DDOTI Optical Observations
  16. Fermi GRB 250411A: Global MASTER-Net observations report
  17. GRB 250411A: Fermi GBM Final Real-time Localization
  18. GRB 250407A: Mondy and AbAO Optical Observations
  19. GRB 250320B: cubesat Avion detection
  20. IPN triangulation of GRB 250407A
  21. GRB 250407A: LCO detection of a fading optical counterpart
  22. Fermi-LAT gamma-ray observations of IceCube-250406A
  23. Konus-Wind detection of GRB 250407A
  24. GRB 250407A: SVOM/GRM observation of a bright long burst
  25. GRB 250407A: EP-WXT afterglow detection
  26. GRB 250407A: COLIBRÍ/DDRAGO Detection of the Optical Counterpart
  27. GRB 250407A: KAIT Optical Afterglow Candidate
  28. GRB 250407A: Fermi GBM Detection
  29. GRB 250407A: Swift-XRT afterglow detection
  30. Fermi GRB 250407A: Global MASTER-Net observations report
  31. GRB 250407A: Swift ToO observations
  32. GRB 250407A: SRG/ART-XC afterglow detection
  33. GRB 250407A: BALROG localization (Fermi Trigger 765733706 / GRB 250407659)
  34. GRB 250407A: Fermi GBM Final Real-time Localization
  35. GRB 250406A: AstroSat CZTI detection
  36. Fermi trigger No 765663719: Global MASTER-Net observations report
  37. Fermi GRB 250406A: Global MASTER-Net observations report
  38. GRB 250404A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  39. GRB 250406A: Fermi GBM Final Real-time Localization
  40. EP250404a / GRB 250404A: Montarrenti Observatory optical observations
  41. Fermi trigger No 765619921: Global MASTER-Net observations report
  42. Fermi Gamma-ray Burst Monitor trigger 765619921/250406342 is not a GRB
  43. GRB 250404A / EP250404a: RC500 INASAN-Kislovodsk optical upper limit
  44. GRB 250404A / EP250404a: SVOM/GWAC-F60 and F50 observations
  45. EP250404a / GRB 250404A: J band observations by SYSU 80cm telescope
  46. Konus-Wind detection of GRB 250404A / EP250404a
  47. GRB 250404A / EP250404a: Mondy optical observations
  48. GRB 250404A / EP250404a: GMG spectroscopic redshift at z ~ 2.627
  49. GRB 250404A / EP250404a: Leavitt Observatory optical counterpart detection
  50. GRB 250404A / EP250404a: NOT optical observations
  51. GRB 250403A: AstroSat CZTI detection
  52. EP250404a: REM optical/NIR observations
  53. EP250404A / GRB250404A: Ondrejov D50 optical afterglow detection
  54. EP250404a: LCO optical counterpart detection
  55. Fermi GRB 250404A: Global MASTER-Net observations report
  56. GRB 250403A: Montarrenti Observatory optical detection
  57. GRB 250404A: Fermi GBM Detection
  58. GRB 250403A: KAIT optical observations
  59. GRB 250402A: Swift/BAT-GUANO localization skymap of a burst
  60. EP250404a: Xinglong-2.16m spectroscopic redshift
  61. GRB 250403A: Fermi GBM observations
  62. EP250404a: Mephisto multi-band optical detection
  63. EP250404a: Nanshan/HMT optical counterpart detection
  64. EP250404a: Einstein Probe detection of an X-ray transient
  65. GRB 250404A: Fermi GBM Final Real-time Localization
  66. GRB 250403A: Swift/UVOT Detection
  67. GRB 250403A: SVOM/VT optical observation
  68. GRB 250403A: REM NIR afterglow detection
  69. GRB 250403A: LCO optical counterpart detection
  70. GRB 250403A: JinShan optical observations
  71. GRB 250403A: Optical counterpart detection by LCO.
  72. GRB 250403A: Swift-XRT observations
  73. Fermi GRB 250403A: Global MASTER-Net observations report
  74. GRB 250403A: GOTO optical counterpart follow-up observations
  75. GRB 250403A: GMG Optical Observation
  76. GRB 250403A: 1.6m Mephisto multi-band optical detection
  77. GRB 250402A: Fermi GBM Observation
  78. GRB 250403A: SVOM/C-GFT optical observations
  79. GRB 250403A: GOTO detection of the optical afterglow
  80. GRB 250403A : SVOM detection of a burst
  81. GRB 250403A: Fermi GBM Final Real-time Localization
  82. GRB 250331E: SVOM/GRM observation
  83. GRB250331D: AbAO optical observations
  84. GRB 250331D: Fermi GBM observation
  85. GRB 250330B: SVOM/GRM observation of a short burst
  86. Fermi GRB 250331E: Global MASTER-Net observations report
  87. Fermi GRB 250331D: Global MASTER-Net observations report
  88. GRB 250330B: EIRSAT-1 GMOD Detection
  89. GRB 250331E: Fermi GBM Final Real-time Localization
  90. Fermi trigger No 765078057: Global MASTER-Net observations report
  91. GRB 250331D: Swift/BAT-GUANO arcminute localization of a burst during slew
  92. Fermi-LAT gamma-ray observations of IceCube-250330A
  93. GRB 250330A: Fermi GBM Observation
  94. GRB 250331D: Fermi GBM Final Real-time Localization
  95. Fermi GRB 250330B: Global MASTER-Net observations report
  96. GRB 250330B: Fermi GBM Final Real-time Localization
  97. Fermi GRB 250330A: Global MASTER-Net observations report
  98. GRB 250330A: BOOTES-7 early optical upper limit
  99. GRB 250330A: Fermi GBM Final Localization
  100. IceCube-250330A - IceCube observation of a high-energy neutrino candidate track-like event

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