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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"

45556 results found.

  1. GRB 250419A: SVOM/VT optical continuous observations
  2. GRB 250419A: SVOM/C-GFT optical observations
  3. GRB 250419A: Swift/UVOT Follow up
  4. GRB 250416C / EP250416a: SVOM/GRM observation of a burst
  5. GRB 250419A: LCO optical afterglow multi-band observations
  6. GRB 250419A: Mondy and AbAO Optical Observations
  7. GRB 250419A: Liverpool Telescope observations
  8. GRB 250419A: AKO Optical Afterglow Detection
  9. GRB 250419A: MASTER optical afterglow observation
  10. Fermi-LAT Gamma-ray Observations of IceCube-250416A
  11. GRB 250407A: rest-frame energetics from Konus-Wind observation
  12. GRB 250419A: Swift-XRT localisation
  13. GRB 250407A: GTC/OSIRIS+ spectroscopic redshift z = 1.36
  14. GRB 250419A: VLT/X-shooter spectroscopic redshift z = 0.845
  15. GRB 250419A: Swift-XRT refined Analysis
  16. GRB 250419A: GOTO optical counterpart detection
  17. GRB 250419A: KAIT optical afterglow observations
  18. GRB 250419A: SVOM/VT optical bright counterpart confirmation
  19. GRB 250419A: SVOM/COLIBRÍ (FM-GFT) Detection of the Optical Counterpart
  20. GRB 250419A: SVOM detection of a soft burst
  21. Konus-Wind detection of GRB 250416C (a counterpart of EP250416a)
  22. EP250416a: Swift/XRT counterpart fading
  23. EP250416a: refined EP-WXT and EP-FXT analysis
  24. Konus-Wind detection of GRB 250403A
  25. EP20250416a: Swift/XRT counterpart detection
  26. GRB 250403A: VLT/FORS2 spectroscopic redshift z = 1.847
  27. IceCube-250416A: DDOTI Optical Observations
  28. EP250416a: Gemini South-GMOS optical counterpart
  29. EP250225a: SVOM/VT optical brightening
  30. SVOM/sb25041603 is not a GRB
  31. EP250416a: GSP optical upper limit
  32. EP250416a: Global MASTER-Net observations report
  33. Fermi Gamma-ray Burst Monitor trigger 766505186/250416588 (GRB 250416A) is not a GRB
  34. EP250416a: Einstein Probe detection of an X-ray transient
  35. IceCube-250416A - IceCube observation of a high-energy neutrino candidate track-like event
  36. IceCube-250416A: Global MASTER-Net observations report
  37. Fermi Gamma-ray Burst Monitor trigger 766511207/250416657 is not a GRB
  38. GRB 250416B: Fermi GBM Final Real-time Localization
  39. GRB 250416A: Fermi GBM Final Real-time Localization
  40. SVOM/sb25041603: SVOM/COLIBRÍ (FM-GFT) Upper Limit on the Optical Counterpart
  41. SVOM/sb25041603: SVOM detection of an X-ray transient
  42. Fermi Gamma-ray Burst Monitor trigger 766474855/250416237 is not a GRB
  43. IceCube 250414.324: DDOTI Optical Observations
  44. GRB 250413A: AstroSat CZTI detection
  45. EP250304a: ATCA radio observations
  46. GRB 250412A: AstroSat CZTI detection
  47. EP250404a: Nanshan 0.43m Telescope optical observatios
  48. Fermi trigger No 766148493: Global MASTER-Net observations report
  49. Fermi trigger No 766173972: Global MASTER-Net observations report
  50. GRB 250411A: DDOTI Optical Observations
  51. Fermi GRB 250411A: Global MASTER-Net observations report
  52. GRB 250411A: Fermi GBM Final Real-time Localization
  53. GRB 250407A: Continued KAIT/Nickel optical observations
  54. GRB 250314A: e-MERLIN observations
  55. GRB 250407A: Mondy and AbAO Optical Observations
  56. EP250227a: Further NOT optical observations
  57. GRB 250320B: cubesat Avion detection
  58. IceCube-250406A: Swift-XRT observations
  59. IPN triangulation of GRB 250321D (consistent with the fast X-ray transient EP250321a)
  60. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-250409A
  61. IPN triangulation of GRB 250407A
  62. EP250407a: Global MASTER-Net observations report
  63. GRB 250407A: LCO detection of a fading optical counterpart
  64. Fermi-LAT gamma-ray observations of IceCube-250406A
  65. EP250407a: Swift-XRT observations
  66. IceCube-250406A: Upper limits from a search for additional neutrino events in IceCube
  67. Konus-Wind detection of GRB 250407A
  68. GRB 250407A: SVOM/GRM observation of a bright long burst
  69. GRB 250407A: EP-WXT afterglow detection
  70. EP250407a: EP-WXT detection of a fast X-ray transient
  71. GRB 250407A: COLIBRÍ/DDRAGO Detection of the Optical Counterpart
  72. GRB 250407A: KAIT Optical Afterglow Candidate
  73. IceCube-250406A: No candidates from the Zwicky Transient Facility
  74. GRB 250407A: Fermi GBM Detection
  75. GRB 250407A: Swift-XRT afterglow detection
  76. Fermi GRB 250407A: Global MASTER-Net observations report
  77. GRB 250407A: Swift ToO observations
  78. GRB 250407A: SRG/ART-XC afterglow detection
  79. LIGO/Virgo/KAGRA S250331o: Upper limits from Swift/BAT-GUANO
  80. IceCube 250406A: DDOTI Optical Observations of the Refined Position
  81. Konus-Wind detection of GRB 250406B (short/hard)
  82. IPN triangulation of GRB 250406B (short/hard)
  83. GRB 250407A: BALROG localization (Fermi Trigger 765733706 / GRB 250407659)
  84. GRB 250407A: Fermi GBM Final Real-time Localization
  85. IceCube-250406A - IceCube observation of a high-energy neutrino candidate track-like event
  86. IceCube 250406.951: COLIBRÍ/DDRAGO Optical Upper Limit
  87. IceCube 250406.951: DDOTI Optical Observations
  88. GRB 250406A: AstroSat CZTI detection
  89. IceCube Alert 250406.95: Global MASTER-Net observations report
  90. Fermi trigger No 765663719: Global MASTER-Net observations report
  91. EP250404a: Multi-band Optical Observations from UCAS-70 and XL-C14
  92. Fermi GRB 250406A: Global MASTER-Net observations report
  93. GRB 250404A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  94. GRB 250406A: Fermi GBM Final Real-time Localization
  95. EP250404a / GRB 250404A: Montarrenti Observatory optical observations
  96. Fermi trigger No 765619921: Global MASTER-Net observations report
  97. Fermi Gamma-ray Burst Monitor trigger 765619921/250406342 is not a GRB
  98. GRB 250404A / EP250404a: RC500 INASAN-Kislovodsk optical upper limit
  99. GRB 250404A / EP250404a: SVOM/GWAC-F60 and F50 observations
  100. EP250404a / GRB 250404A: J band observations by SYSU 80cm telescope

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