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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"

28196 results found.

  1. EP250911a: refined analysis of the EP-WXT and EP-FXT observations
  2. EP250911a: SVOM/VT optical observation
  3. GRB 250911A: MASTER optical counterpart observations
  4. GRB 250911A: Swift-XRT refined Analysis
  5. GRB 250910C: Fermi GBM Final Localization Correction
  6. EP250911a: Swift-XRT observations
  7. EP250911a: Optical detection with Kinder observations
  8. GRB 250911A: Swift/UVOT Detection
  9. GRB 250910A / EP250910a: Swift-XRT afterglow detection
  10. GRB 250910A / EP250910a: SVOM/VT afterglow confirmation
  11. GRB 250909B: Insight-HXMT detection
  12. GRB 250910A / EP250910a : VLT/HAWK-I NIR counterpart discovery
  13. EP250911a: LCO optical counterpart discovery
  14. EP250911a: Einstein Probe detection of an X-ray transient
  15. GRB 250911A: Enhanced Swift-XRT position
  16. GRB 250911A: Swift-XRT observations
  17. GRB 250911A: Swift detection of a burst
  18. GRB 250910B: Fermi GBM Final Real-time Localization
  19. GRB 250910A / EP250910a: VLT/HAWK-I near-infrared observations
  20. EP250910a/GRB 250910A: EP-WXT detection of a fast X-ray transient
  21. GRB 250909B: AstroSat CZTI detection of a long burst
  22. GRB 250909A: AstroSat CZTI detection
  23. GRB 250910A: SVOM/MXT possible afterglow detection
  24. GRB 250910A: SVOM detection of a faint burst
  25. LIGO/Virgo/KAGRA S250910b: Retraction of GW compact binary merger candidate
  26. GRB 250702B: Late time Chandra observations
  27. EP250908b/EP#01709240653: Swift/UVOT Detection
  28. EP#01709240653: Swift-XRT observations
  29. GRB 250907A: CALET Gamma-Ray Burst Monitor detection
  30. EP250908c: VLT/FORS2 optical counterpart identification
  31. EP250908c: Einstein Probe detection of an X-ray transient
  32. GRB 250909A: Fermi GBM Final Real-time Localization
  33. EP250908b: EP-WXT detection of a fast X-ray transient and EP-FXT observation
  34. GRB 250907A: GECAM-B detection
  35. GRB 250903A: Swift-XRT afterglow detection
  36. SVOM/sb25090605: detection of an X-ray transient from the LMXB 4U 0513-40
  37. EP250905b: EP-FXT follow-up observation
  38. EP250905a: Liverpool Telescope observations
  39. EP250905b: EP-WXT detection of a fast X-ray transient
  40. GRB 250905A: Swift-XRT refined Analysis
  41. EP250905a: JinShan likely optical counterpart detection
  42. IceCube-250905A - IceCube observation of a high-energy neutrino candidate track-like event
  43. GRB 250905A: Swift/UVOT Upper Limits
  44. EP250905a: Einstein Probe detection of an X-ray transient
  45. GRB 250905B: Fermi GBM Final Localization
  46. GRB250904A: Liverpool Telescope upper limits
  47. GRB 250905A: Enhanced Swift-XRT position
  48. GRB 250904A: Swift/UVOT Detection
  49. GRB 250903A: Swift/UVOT detection
  50. GRB 250904A: Swift-XRT refined Analysis
  51. EP detected a brightening of LMXB 1ES 1735-26.9
  52. GRB 250905A: KAIT optical upper limit
  53. GRB 250905A: Swift detection of a burst
  54. GRB 250904A: Enhanced Swift-XRT position
  55. GRB 250904A: TRT optical counterpart detection
  56. GRB 250902B: CALET Gamma-Ray Burst Monitor detection
  57. GRB 250904A: Prompt enhanced Swift-XRT position
  58. GRB 250904A: Swift detection of a burst
  59. GRB 250902A: CALET Gamma-Ray Burst Monitor detection
  60. GRB 250902A: VZLUSAT-2 detection
  61. GRB 250903A: Swift-XRT observations
  62. EP250903a: Swift-XRT observations
  63. EP#01709201209: Swift-XRT observations
  64. EP250903a: retraction of the LCO candidate, and discovery of the likely counterpart
  65. EP-WXT trigger 01709201209: Liverpool Telescope upper limits
  66. GRB 250830C: VZLUSAT-2 detection
  67. GRB 250903A: VLT X-shooter spectroscopic redshift z = 1.590
  68. GRB 250903A: EP-FXT counterpart detection
  69. GRB 250902A: GECAM-B detection
  70. GRB 250903A: LCO optical observation
  71. GRB 250903A: LCO optical afterglow detection
  72. EP250901a: Mondy, Assy and SAO RAS optical limits
  73. Subject GRB 250903A: SVOM/MXT afterglow detection
  74. EP250903a: LCO candidate counterpart discovery
  75. GRB 250903A: TRT optical counterpart detection
  76. GRB 250902B: AstroSat CZTI detection
  77. GRB 250903A: SVOM detection of a burst
  78. EP250903a: Einstein Probe detection of an X-ray transient
  79. EP 250827B: Detection of supernova counterpart by LCO.
  80. EP250827b: continued Liverpool Telescope observations
  81. EP250827b: SVOM/VT observation of AT 2025wkm
  82. GRB 250902A: Fermi GBM Detection
  83. GRB 250901A: Swift/UVOT Upper Limit
  84. GRB 250902B: Fermi GBM Final Real-time Localization
  85. GRB 250830B: Swift-XRT afterglow detection
  86. EP250827b: Liverpool Telescope observations
  87. GRB 250831A (SVOM trigger sb25083102): confirmation of a stellar flare by SVOM/VT
  88. EP250828a: Early near-infrared follow-up with MIRAGE on the MDM 1.3m telescope
  89. EP250901a: refined analysis of the EP-WXT and EP-FXT observations
  90. GRB 250901A: EP-FXT follow-up observation
  91. GRB 250901A: NOT optical observations
  92. GRB 250902A: Fermi GBM Final Real-time Localization
  93. GRB 250901A: SVOM/VT optical afterglow with VHF data
  94. GRB 250901A: Swift-XRT afterglow detection
  95. EP250901a: Swift-XRT observations
  96. GRB 250901A: LCO optical upper limit
  97. EP250827b: Swift observations of AT 2025wkm
  98. EP250831a: NOT optical observations and tentative afterglow candidate
  99. EP250827b: Contemporaneous detection of EP X-ray flare EP250827b and ZTF transient ZTF25abmpngy/AT2025wkm
  100. GRB 250901A: SVOM detection of a burst

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