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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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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

28115 results found.

  1. Corrected Swift-XRT Refined Analysis of GRB 250809A
  2. GRB 250809A: Swift-XRT refined Analysis
  3. GRB 250809A: LCOGT Optical Upper Limits
  4. GRB 250702B: Chandra X-ray Detection
  5. GRB 250808A: VLT X-shooter candidate counterpart
  6. GRB 250809A: Prompt enhanced Swift-XRT position
  7. GRB 250809A: Swift detection of a gamma ray burst
  8. GRB 250808A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  9. GRB 250808A: Swift-XRT candidate counterpart detection
  10. GRB 250807A: SVOM/VT optical continued observation
  11. GRB 250808A: SVOM detection of a long burst
  12. GRB 250808A: Fermi GBM Final Real-time Localization
  13. Konus-Wind detection of GRB 250807A
  14. GRB 250807B: Swift/UVOT Detection
  15. GRB 250807B: Kilonova-Catcher optical afterglow detection
  16. GRB 250807A: Swift/UVOT Detection
  17. GRB 250807A: Swift-XRT refined Analysis
  18. GRB 250806A: SVOM/MXT refined analysis
  19. GRB 250806A: SVOM/ECLAIRs refined analysis
  20. GRB 250804B: Insight-HXMT detection
  21. GRB 250807A: AstroSat CZTI detection of bright long burst
  22. GRB 250807B: Swift-XRT refined Analysis
  23. GRB 250806A: NOT z-band upper limit and host galaxy candidate
  24. GRB 250807B: NTT optical observations
  25. EP250807a: EP-WXT detection of a fast X-ray transient
  26. GRB 250807A: SVOM/VT optical observation
  27. GRB 250807B: Enhanced Swift-XRT position
  28. GRB 250807A: Enhanced Swift-XRT position
  29. GRB 250807B: Swift detection of a burst with an optical counterpart.
  30. GRB 250805A: Kilonova-Catcher optical upper limits
  31. GRB 250805A: Swift/UVOT Upper Limits
  32. GRB 250806A: Swift/UVOT U-band detection
  33. GRB 250807A: Swift detection of a burst with an optical counterpart
  34. GRB 250806A: EP-FXT observation
  35. EP#01709198415/EP250806a: Swift-XRT observations
  36. EP250802a: EP-FXT follow-up observation
  37. EP250806a: Earlier Detection of the VT Candidate by COLIBRÍ and LS
  38. GRB 250806A: J-band upper limit from WINTER
  39. GRB 250806A: KAIT optical upper limit
  40. GRB 250806A: SVOM/VT refined analysis
  41. GRB 250806A: Swift-XRT counterpart detection
  42. EP250806a: Einstein Probe detection of an X-ray transient
  43. GRB 250806A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  44. GRB 250806A: SVOM detection of a soft burst
  45. GRB 250805A: SVOM/VT optical counterpart
  46. GRB 250805A: ESO/VLT observations
  47. GRB 250805A: Swift-XRT refined Analysis
  48. GRB 250804B: Swift-XRT observations
  49. GRB 250805A: Enhanced Swift-XRT position
  50. GRB 250804C: AstroSat CZTI detection of a long burst
  51. GRB 250805A: TRT optical upper limits
  52. IceCube-250804A - IceCube observation of a high-energy neutrino candidate track-like event
  53. GRB 250805A: Swift-XRT observations
  54. GRB 250805A: Swift detection of a burst
  55. GRB 250804B: Tiled Swift observations
  56. GRB 250804A: Fermi GBM Final Localization
  57. EP250802a: additional Liverpool Telescope upper limits
  58. EP250802a: GROWTH-India Telescope optical upper limit
  59. EP250802a: Einstein Probe detection of an X-ray transient
  60. LIGO/Virgo/KAGRA S250725j: GOTO pre-trigger detection of AT2025sib
  61. LIGO/Virgo/KAGRA S250727dc: DECam DESGW Epoch 1 Candidates
  62. GRB 250727A: Swift-XRT afterglow confirmation and refined analysis
  63. EP250730a: Einstein Probe detection of an X-ray transient
  64. LIGO/Virgo/KAGRA S250727dc: Swift-XRT observations, 8 X-ray sources
  65. GRB 250725A: AstroSat CZTI detection
  66. GRB 250727A: EP-FXT follow-up observation
  67. GRB 250725A: PRIME near-infrared observations
  68. LIGO/Virgo/KAGRA S250727dc: PRIME J-band upper limits of AT 2025smm
  69. GRB: Clarification on Gamma-Ray Burst Naming Convention
  70. GRB 250728A: Swift-XRT observations
  71. EP-WXT trigger 01709195487: confirmation of a stellar flare by BOOTES-6 & BOOTES-7
  72. GRB 250728A: COLIBRÍ optical upper limit
  73. LIGO/Virgo/KAGRA S250727dc: Swift-UVOT detection of a new source, AT 2025smm
  74. GRB 250728A: Swift ToO observations
  75. GRB 250728A: Swift/BAT-GUANO arcminute localization of a short burst
  76. GRB 250727A: AST3-2 Upper limit
  77. GRB 250727A: EP-FXT counterpart detection
  78. GRB250727A: SVOM/VT optical upper limit
  79. GRB 250727A: Swift-XRT observations
  80. GRB 250727A: SVOM detection of a burst
  81. Swift detection of the Soft Gamma Repeater PSR J1647-4552
  82. GRB 250725A: Swift-XRT refined Analysis
  83. GRB 250725A: Fermi GBM Observation
  84. Konus-Wind detection of GRB 250725A
  85. GRB 250725A: Swift/UVOT Upper Limits
  86. GRB 250725A: Fermi-LAT detection
  87. GRB 250725A: VLT/FORS2 spectroscopic redshift z = 5.26
  88. GRB 250725A: BOOTES-7 early optical detection
  89. GRB 250725A: SVOM/VT optical candidate
  90. GRB 250725A: MASTER-OAFA optical detection of very fast afterglow
  91. GRB 250725A: Enhanced Swift-XRT position
  92. GRB 250725A: Swift detection of a burst
  93. Swift GRB 250725A: Global MASTER-Net OT detection
  94. GRB 250725A: Fermi GBM Final Real-time Localization
  95. EP250702a/GRB250702 B,E,D: MeerKAT radio observations at 3.06 GHz
  96. EP250702a/GRB250702 B,D,E: uGMRT Radio detection in 1.26 GHz
  97. SVOM J195836+32283/sb25072103: Liverpool Telescope detection of an extended source
  98. GRB 250723B: Fermi GBM Final Real-time Localization
  99. GRB 250723A: Fermi GBM Final Real-time Localization
  100. SVOM J195836+32283/sb25072103: Swift XRT/UVOT upper limits

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