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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"

37996 results found.

  1. GRB 250419A: LCO optical afterglow multi-band observations
  2. GRB 250419A: Mondy and AbAO Optical Observations
  3. GRB 250419A: Liverpool Telescope observations
  4. GRB 250419A: AKO Optical Afterglow Detection
  5. GRB 250419A: MASTER optical afterglow observation
  6. GRB 250407A: rest-frame energetics from Konus-Wind observation
  7. GRB 250419A: Swift-XRT localisation
  8. GRB 250407A: GTC/OSIRIS+ spectroscopic redshift z = 1.36
  9. GRB 250419A: VLT/X-shooter spectroscopic redshift z = 0.845
  10. GRB 250419A: Swift-XRT refined Analysis
  11. GRB 250419A: GOTO optical counterpart detection
  12. GRB 250419A: KAIT optical afterglow observations
  13. GRB 250419A: SVOM/VT optical bright counterpart confirmation
  14. GRB 250419A: SVOM/COLIBRÍ (FM-GFT) Detection of the Optical Counterpart
  15. GRB 250419A: SVOM detection of a soft burst
  16. Konus-Wind detection of GRB 250416C (a counterpart of EP250416a)
  17. EP250416a: Swift/XRT counterpart fading
  18. Konus-Wind detection of GRB 250403A
  19. EP20250416a: Swift/XRT counterpart detection
  20. GRB 250403A: VLT/FORS2 spectroscopic redshift z = 1.847
  21. SVOM/sb25041603 is not a GRB
  22. Fermi Gamma-ray Burst Monitor trigger 766505186/250416588 (GRB 250416A) is not a GRB
  23. Fermi Gamma-ray Burst Monitor trigger 766511207/250416657 is not a GRB
  24. GRB 250416B: Fermi GBM Final Real-time Localization
  25. GRB 250416A: Fermi GBM Final Real-time Localization
  26. Fermi Gamma-ray Burst Monitor trigger 766474855/250416237 is not a GRB
  27. GRB 250413A: AstroSat CZTI detection
  28. EP250304a: ATCA radio observations
  29. GRB 250412A: AstroSat CZTI detection
  30. GRB 250411A: DDOTI Optical Observations
  31. Fermi GRB 250411A: Global MASTER-Net observations report
  32. GRB 250411A: Fermi GBM Final Real-time Localization
  33. GRB 250407A: Continued KAIT/Nickel optical observations
  34. GRB 250314A: e-MERLIN observations
  35. GRB 250407A: Mondy and AbAO Optical Observations
  36. GRB 250320B: cubesat Avion detection
  37. IceCube-250406A: Swift-XRT observations
  38. IPN triangulation of GRB 250321D (consistent with the fast X-ray transient EP250321a)
  39. IPN triangulation of GRB 250407A
  40. GRB 250407A: LCO detection of a fading optical counterpart
  41. EP250407a: Swift-XRT observations
  42. Konus-Wind detection of GRB 250407A
  43. GRB 250407A: SVOM/GRM observation of a bright long burst
  44. GRB 250407A: EP-WXT afterglow detection
  45. GRB 250407A: COLIBRÍ/DDRAGO Detection of the Optical Counterpart
  46. GRB 250407A: KAIT Optical Afterglow Candidate
  47. GRB 250407A: Fermi GBM Detection
  48. GRB 250407A: Swift-XRT afterglow detection
  49. Fermi GRB 250407A: Global MASTER-Net observations report
  50. GRB 250407A: Swift ToO observations
  51. GRB 250407A: SRG/ART-XC afterglow detection
  52. LIGO/Virgo/KAGRA S250331o: Upper limits from Swift/BAT-GUANO
  53. Konus-Wind detection of GRB 250406B (short/hard)
  54. IPN triangulation of GRB 250406B (short/hard)
  55. GRB 250407A: BALROG localization (Fermi Trigger 765733706 / GRB 250407659)
  56. GRB 250407A: Fermi GBM Final Real-time Localization
  57. GRB 250406A: AstroSat CZTI detection
  58. Fermi GRB 250406A: Global MASTER-Net observations report
  59. GRB 250404A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  60. GRB 250406A: Fermi GBM Final Real-time Localization
  61. EP250404a / GRB 250404A: Montarrenti Observatory optical observations
  62. Fermi Gamma-ray Burst Monitor trigger 765619921/250406342 is not a GRB
  63. GRB 250404A / EP250404a: RC500 INASAN-Kislovodsk optical upper limit
  64. GRB 250404A / EP250404a: SVOM/GWAC-F60 and F50 observations
  65. EP250404a / GRB 250404A: J band observations by SYSU 80cm telescope
  66. Konus-Wind detection of GRB 250404A / EP250404a
  67. GRB 250404A / EP250404a: Mondy optical observations
  68. GRB 250404A / EP250404a: GMG spectroscopic redshift at z ~ 2.627
  69. GRB 250404A / EP250404a: Leavitt Observatory optical counterpart detection
  70. GRB 250402A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  71. GRB 250404A / EP250404a: NOT optical observations
  72. GRB 250331D: Swift-XRT afterglow detection
  73. GRB 250404B: AstroSat CZTI detection of a short burst
  74. GRB 250403A: AstroSat CZTI detection
  75. EP250404a: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  76. EP250404a: REM optical/NIR observations
  77. EP250404A / GRB250404A: Ondrejov D50 optical afterglow detection
  78. EP250404a: LCO optical counterpart detection
  79. Fermi GRB 250404A: Global MASTER-Net observations report
  80. GRB 250403A: Montarrenti Observatory optical detection
  81. GRB 250404A: Fermi GBM Detection
  82. GRB 250403A: KAIT optical observations
  83. GRB 250402A: Swift/BAT-GUANO localization skymap of a burst
  84. EP250404a: Xinglong-2.16m spectroscopic redshift
  85. GRB 250403A: Fermi GBM observations
  86. GRB 250327B: VIRT Optical Upper Limit
  87. GRB 250331C Swift-BAT refined analysis
  88. GRB 250331B Swift-BAT refined analysis
  89. GRB 250330A Swift-BAT refined analysis
  90. EP250321A: J band upper limit by SYSU 80cm telescope
  91. EP250404a: Nanshan/HMT optical counterpart detection
  92. EP250404a: Einstein Probe detection of an X-ray transient
  93. GRB 250404A: Fermi GBM Final Real-time Localization
  94. GRB 250402A: Mondy optical observations
  95. GRB 250403A: Swift/UVOT Detection
  96. GRB 250402A: Swift/UVOT Upper Limits
  97. GRB 250403A: SVOM/VT optical observation
  98. GRB 250403A: REM NIR afterglow detection
  99. GRB 250403A: LCO optical counterpart detection
  100. GRB 250403A: JinShan optical observations

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