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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"

36346 results found.

  1. GRB 250421B: AstroSat CZTI detection of a bright long burst
  2. GRB 250421A: Fermi GBM Final Real-time Localization
  3. GRB 250419A: Liverpool Telescope observations
  4. GRB 250419A: LCO optical observation
  5. GRB 250419A: JinShan optical observations
  6. GRB 250419A: SVOM/VT optical continuous observations
  7. GRB 250419A: SVOM/C-GFT optical observations
  8. GRB 250419A: Swift/UVOT Follow up
  9. GRB 250416C / EP250416a: SVOM/GRM observation of a burst
  10. GRB 250419A: LCO optical afterglow multi-band observations
  11. GRB 250419A: Mondy and AbAO Optical Observations
  12. GRB 250419A: Liverpool Telescope observations
  13. GRB 250419A: AKO Optical Afterglow Detection
  14. GRB 250419A: MASTER optical afterglow observation
  15. GRB 250407A: rest-frame energetics from Konus-Wind observation
  16. GRB 250419A: Swift-XRT localisation
  17. GRB 250407A: GTC/OSIRIS+ spectroscopic redshift z = 1.36
  18. GRB 250419A: VLT/X-shooter spectroscopic redshift z = 0.845
  19. GRB 250419A: Swift-XRT refined Analysis
  20. GRB 250419A: GOTO optical counterpart detection
  21. GRB 250419A: KAIT optical afterglow observations
  22. GRB 250419A: SVOM/VT optical bright counterpart confirmation
  23. GRB 250419A: SVOM/COLIBRÍ (FM-GFT) Detection of the Optical Counterpart
  24. GRB 250419A: SVOM detection of a soft burst
  25. Konus-Wind detection of GRB 250416C (a counterpart of EP250416a)
  26. Konus-Wind detection of GRB 250403A
  27. GRB 250403A: VLT/FORS2 spectroscopic redshift z = 1.847
  28. SVOM/sb25041603 is not a GRB
  29. Fermi Gamma-ray Burst Monitor trigger 766505186/250416588 (GRB 250416A) is not a GRB
  30. Fermi Gamma-ray Burst Monitor trigger 766511207/250416657 is not a GRB
  31. GRB 250416B: Fermi GBM Final Real-time Localization
  32. GRB 250416A: Fermi GBM Final Real-time Localization
  33. Fermi Gamma-ray Burst Monitor trigger 766474855/250416237 is not a GRB
  34. GRB 250413A: AstroSat CZTI detection
  35. EP250304a: ATCA radio observations
  36. GRB 250412A: AstroSat CZTI detection
  37. GRB 250411A: DDOTI Optical Observations
  38. Fermi GRB 250411A: Global MASTER-Net observations report
  39. GRB 250411A: Fermi GBM Final Real-time Localization
  40. GRB 250407A: Continued KAIT/Nickel optical observations
  41. GRB 250314A: e-MERLIN observations
  42. GRB 250407A: Mondy and AbAO Optical Observations
  43. GRB 250320B: cubesat Avion detection
  44. IPN triangulation of GRB 250321D (consistent with the fast X-ray transient EP250321a)
  45. IPN triangulation of GRB 250407A
  46. GRB 250407A: LCO detection of a fading optical counterpart
  47. EP250407a: Swift-XRT observations
  48. IceCube-250406A: Upper limits from a search for additional neutrino events in IceCube
  49. Konus-Wind detection of GRB 250407A
  50. GRB 250407A: SVOM/GRM observation of a bright long burst
  51. GRB 250407A: EP-WXT afterglow detection
  52. GRB 250407A: COLIBRÍ/DDRAGO Detection of the Optical Counterpart
  53. GRB 250407A: KAIT Optical Afterglow Candidate
  54. GRB 250407A: Fermi GBM Detection
  55. GRB 250407A: Swift-XRT afterglow detection
  56. Fermi GRB 250407A: Global MASTER-Net observations report
  57. GRB 250407A: Swift ToO observations
  58. GRB 250407A: SRG/ART-XC afterglow detection
  59. LIGO/Virgo/KAGRA S250331o: Upper limits from Swift/BAT-GUANO
  60. Konus-Wind detection of GRB 250406B (short/hard)
  61. IPN triangulation of GRB 250406B (short/hard)
  62. GRB 250407A: BALROG localization (Fermi Trigger 765733706 / GRB 250407659)
  63. GRB 250407A: Fermi GBM Final Real-time Localization
  64. GRB 250406A: AstroSat CZTI detection
  65. Fermi GRB 250406A: Global MASTER-Net observations report
  66. GRB 250404A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  67. GRB 250406A: Fermi GBM Final Real-time Localization
  68. EP250404a / GRB 250404A: Montarrenti Observatory optical observations
  69. Fermi Gamma-ray Burst Monitor trigger 765619921/250406342 is not a GRB
  70. GRB 250404A / EP250404a: RC500 INASAN-Kislovodsk optical upper limit
  71. GRB 250404A / EP250404a: SVOM/GWAC-F60 and F50 observations
  72. EP250404a / GRB 250404A: J band observations by SYSU 80cm telescope
  73. Konus-Wind detection of GRB 250404A / EP250404a
  74. GRB 250404A / EP250404a: Mondy optical observations
  75. GRB 250404A / EP250404a: GMG spectroscopic redshift at z ~ 2.627
  76. GRB 250404A / EP250404a: Leavitt Observatory optical counterpart detection
  77. GRB 250402A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  78. GRB 250404A / EP250404a: NOT optical observations
  79. GRB 250331D: Swift-XRT afterglow detection
  80. GRB 250404B: AstroSat CZTI detection of a short burst
  81. GRB 250403A: AstroSat CZTI detection
  82. EP250404a: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  83. EP250404a: REM optical/NIR observations
  84. EP250404A / GRB250404A: Ondrejov D50 optical afterglow detection
  85. EP250404a: LCO optical counterpart detection
  86. Fermi GRB 250404A: Global MASTER-Net observations report
  87. GRB 250403A: Montarrenti Observatory optical detection
  88. GRB 250404A: Fermi GBM Detection
  89. GRB 250403A: KAIT optical observations
  90. GRB 250402A: Swift/BAT-GUANO localization skymap of a burst
  91. EP250404a: Xinglong-2.16m spectroscopic redshift
  92. GRB 250403A: Fermi GBM observations
  93. GRB 250327B: VIRT Optical Upper Limit
  94. GRB 250331C Swift-BAT refined analysis
  95. GRB 250331B Swift-BAT refined analysis
  96. GRB 250330A Swift-BAT refined analysis
  97. EP250404a: BOOTES-4/JGT optical afterglow detection
  98. EP250404a: Nanshan/HMT optical counterpart detection
  99. EP250404a: Einstein Probe detection of an X-ray transient
  100. GRB 250404A: Fermi GBM Final Real-time Localization

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