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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"

20008 results found.

  1. GRB 250127A: Swift ToO observations
  2. GECAM-A detection of a bright burst from SGR 1E1841-045
  3. GRB 250118A: Fermi GBM Observation
  4. EP250125a: REM optical counterpart detection
  5. GRB 250119C: Fermi GBM Observation
  6. EP250125a: Swift/XRT detection of a fading counterpart
  7. Konus-Wind detection of a bright burst from SGR 1E1841-045 on 2025 January 23
  8. GRB 250121A: Swift/BAT-GUANO localization skymap of a burst
  9. IPN triangulation of a bright burst from SGR 1E1841-045
  10. IPN triangulation of GRB 250118B
  11. Konus-Wind detection of GRB 250119B
  12. IPN triangulation of GRB 250119B
  13. Improved IPN triangulation of GRB 250107C
  14. GRB 250114A: Swift-BAT refined analysis
  15. LIGO/Virgo S250119cv: Swift XRT observations, 5 X-ray sources
  16. GRB 250119C: Swift/BAT-GUANO localization skymap of a short burst
  17. GRB 250119B: Swift/BAT-GUANO localization skymap of a long burst
  18. GRB 250118A: Swift/BAT-GUANO localization skymap of a short burst
  19. Konus-Wind detection of GRB 250117A
  20. IPN triangulation of GRB 250117A (short)
  21. GRB 250117A: SVOM/GRM observation of a short burst
  22. GRB 250117A: Swift/BAT-GUANO localization skymap of a short burst
  23. GRB 250116A: GECAM-B detection of a long burst
  24. Swift Trigger 1282245 is not a GRB
  25. GRB 250114B: Swift-XRT afterglow detection
  26. GRB 250101A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations and rebrightening.
  27. IPN triangulation of GRB 250113A
  28. GRB 250114B: Swift-XRT observations
  29. GRB 250114A: LCO optical counterpart detection.
  30. GRB 250114A: GRANDMA/TAROT optical afterglow detection
  31. GRB 250114A: Swift-XRT refined Analysis
  32. GRB 250114A: LCOGT optical afterglow i-band detection
  33. GRB 250114B: Swift ToO observations
  34. EP250111a: SAO RAS optical upper limit
  35. GRB 250114A: Enhanced Swift-XRT position
  36. GRB 250114A: REM detection of the optical and NIR counterpart
  37. Swift GRB250114A: Global MASTER-Net OT detection
  38. GRB 250114A: LCO optical observations
  39. GRB 250114A: TRT optical observations
  40. Swift GRB 250114A: Global MASTER-Net observations report
  41. GRB 250114A: Swift detection of a burst with an optical counterpart
  42. GRB 250107A: VZLUSAT-2 detection
  43. GRB 250109A / EP250109a: GRBAlpha detection
  44. GRB 250106A: Swift-XRT afterglow detection
  45. GRB 250109A / EP250109a: Mephisto optical upper limits
  46. EP250111a: Swift/XRT detection and fading
  47. EP250108a / AT 2025kg: Swift UVOT detections
  48. GRB 250109A / EP250109A: Swift/BAT-GUANO localization skymap of a burst
  49. GRB 250109A / EP250109a: Swift detection of the X-ray afterglow
  50. GRB 250108A: Swift/XRT afterglow fading
  51. EP250109a / GRB 250109A: refined EP-WXT analysis and EP-FXT follow-up observation
  52. EP250109a: Swift/UVOT non-detection
  53. IPN triangulation of GRB 250107D (short/hard)
  54. IPN triangulation of GRB 250107C
  55. GRB 250108B: Swift-BAT refined analysis
  56. GRB 250108B: 1.3m DFOT upper limit
  57. GRB 250108B: REM optical/NIR upper limits
  58. EP250109a: GOTO optical upper limits
  59. EP250109a: Swift/XRT non-detection
  60. GRB 250108A: Swift/UVOT Upper Limits
  61. GRB 250108A: NOT optical upper limit
  62. GRB 250108B: Swift-XRT refined Analysis
  63. Swift GRB 250108B: Global MASTER-Net observations report
  64. GRB 250108A: Swift-XRT afterglow detection
  65. GRB 250108B: Swift/UVOT Upper Limits
  66. GRB 250103A: Swift-XRT afterglow detection
  67. GRB 250108B: Enhanced Swift-XRT position
  68. GRB 250108B: Swift detection of a burst
  69. GRB 250108A: Swift ToO observations
  70. GRB 250107A: Fermi GBM Observation
  71. GRB 241228B: Fermi-LAT detection
  72. GRB 250107A: Swift ToO observations
  73. GRB 250107A: Swift/BAT-GUANO arcminute localization of a burst
  74. GRB 250106A: NOT optical observations
  75. GRB 250103B: REM optical/NIR upper limits
  76. GRB 250101A: REM optical/NIR counterpart detection
  77. GRB 250106A: Swift-XRT observations
  78. GRB 250106A: Swift ToO observations
  79. GRB 241229A: SVOM/VT optical upperlimit
  80. GRB 250103B: Swift-XRT refined Analysis
  81. GRB 250103B: LCO/1m optical afterglow candidate detection
  82. GRB 250103A: Swift-XRT observations
  83. GRB 250101A: 1.3m DFOT optical afterglow detection
  84. GRB 241229A: 1.3m DFOT upper limit
  85. GRB 241228A: 1.3m DFOT upper limit
  86. GRB 250103B:SVOM/VT optical counterpart
  87. GRB 250101A: further LCOGT optical afterglow observations
  88. GRB 250103B: LCOGT Optical Upper Limit
  89. Swift GRB 250103B: Global MASTER-Net observations report
  90. GRB 250103A: Swift ToO observations
  91. GRB 250101a: Liverpool Telescope optical follow-up
  92. GRB 250103B: SVOM detection of a long burst
  93. GRB 250103B: Swift detection of a burst
  94. LIGO/Virgo/KAGRA S241230bd: Upper limits from Swift/BAT-GUANO
  95. GRB 250101A: Swift-BAT refined analysis
  96. GRB 250101A: further SAO RAS optical observations
  97. GRB 250101A: LCO optical counterpart detection
  98. GRB 250101A: GMG spectroscopic redshift at z ~ 2.481
  99. GRB 250101A: Swift/UVOT Detection
  100. GRB 250101A: 1.6m Mephisto multi-band optical followup

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