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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"

43045 results found.

  1. GRB 250813B: SVOM detection of a bright long burst (Correction for GCN 41352).
  2. GRB 250813B: Ondrejov D50 optical afterglow detection
  3. GRB 250813B: SVOM detection of a bright long burst
  4. LIGO/Virgo/KAGRA S250813k: NED Galaxies in the 4-Update Localization Volume
  5. LIGO/Virgo/KAGRA S250813k: Updated Sky localization
  6. EP250812a: Nickel optical upper limit
  7. GRB 250812A: VLT X-shooter spectroscopic redshift confirmation z = 2.571
  8. GRB 250812A: NTT spectroscopic redshift z = 2.57
  9. GRB250812a: STEP/T80S Indication of slow decay of afterglow
  10. EP250812a: NOT, NTT, and GS observations
  11. GRB 250812A: Swift/UVOT Detection
  12. GRB 250813A: Fermi GBM Final Localization
  13. EP250812a: COLIBRÍ detection of the VT candidate and evidence of flattening
  14. EP250812a: Liverpool Telescope upper limits
  15. EP250812a: SVOM/VT optical counterpart
  16. EP250812a: refined analysis of the EP-WXT and EP-FXT observations
  17. IceCube-250813A - IceCube observation of a high-energy neutrino candidate track-like event
  18. IceCube Alert 250813.14: Global MASTER-Net observations report
  19. LIGO/Virgo/KAGRA S250813k: Identification of a GW compact binary merger candidate
  20. GRB 250812A: EP-FXT counterpart detection
  21. GRB 250812A: Swift ToO observations
  22. EP 250812a: GOTO optical upper limit
  23. GRB 250812A: Kilonova-Catcher optical afterglow detection
  24. EP250812a: Swift-XRT counterpart detection
  25. GRB 250812A: SVOM/COLIBRÍ (FM-GFT) optical observations
  26. EP250812a: Einstein Probe detection of an X-ray transient
  27. GRB 250812A: SVOM/VT optical afterglow confirmation
  28. GRB 250812A: Swift-XRT afterglow detection
  29. GRB 250812A: TRT likely optical counterpart detection
  30. IceCube-Cascade 250809A: Upper limits from a search for additional neutrino events in IceCube
  31. GRB 250812A: SVOM detection of a faint long burst
  32. Fermi-LAT Gamma-ray Observations of IceCube-250804A
  33. LIGO/Virgo/KAGRA S250810ck: Updated Sky localization and EM Bright Classification
  34. GRB 250809A: Swift/UVOT Detection
  35. LIGO/Virgo/KAGRA S250810ck: Identification of a GW compact binary merger candidate
  36. GRB 250809A: Swift-XRT refined Analysis
  37. GRB 250807B: SVOM/VT optical observation
  38. EP250807a: EP-FXT follow-up observation upper limit
  39. GRB 250809A: LCOGT Optical Upper Limits
  40. GRB 250702B: Chandra X-ray Detection
  41. EP250807a: Global MASTER-Net observations report
  42. Fermi GRB 250808A: Global MASTER-Net observations report
  43. GRB 250808A: VLT X-shooter candidate counterpart
  44. GRB 250809A: Prompt enhanced Swift-XRT position
  45. GRB 250809A: Swift detection of a gamma ray burst
  46. GRB 250808A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  47. GRB 250808A: Fermi GBM Observation
  48. GRB 250808A: Swift-XRT candidate counterpart detection
  49. GRB 250807A: SVOM/VT optical continued observation
  50. EP-WXT trigger 01709195487: KAIT confirmation of the stellar flare
  51. GRB 250808A: SVOM detection of a long burst
  52. GRB 250808A: Fermi GBM Final Real-time Localization
  53. Konus-Wind detection of GRB 250807A
  54. GRB 250807B: Swift/UVOT Detection
  55. GRB 250807B: Kilonova-Catcher optical afterglow detection
  56. IceCube-250804A: Upper limits from a search for additional neutrino events in IceCube
  57. GRB 250807A: Swift/UVOT Detection
  58. GRB 250807A: Swift-XRT refined Analysis
  59. GRB 250807B: VLT/X-Shooter spectroscopic redshift z = 1.522
  60. GRB 250806A: SVOM/MXT refined analysis
  61. GRB 250806A: SVOM/ECLAIRs refined analysis
  62. EP250807a: NTT z-band optical upper limit
  63. GRB 250806A: Mondy optical observations, and nearby bright galaxy photometry
  64. GRB 250804B: Insight-HXMT detection
  65. GRB 250807A: SVOM/GRM observation
  66. Swift GRB250807.45: Global MASTER-Net observations report
  67. GRB 250807A: AstroSat CZTI detection of bright long burst
  68. GRB 250807B: Swift-XRT refined Analysis
  69. GRB 250806A: NOT z-band upper limit and host galaxy candidate
  70. GRB 250807B: NTT optical observations
  71. EP250807a: EP-WXT detection of a fast X-ray transient
  72. EP 250807.979: GOTO optical upper limit
  73. EP250807a: COLIBRÍ optical upper limit
  74. GRB 250807A: SVOM/VT optical observation
  75. EP250806a: Upper limit from Fermi-GBM Observations
  76. GRB 250807B: Enhanced Swift-XRT position
  77. Swift GRB250807.65: Global MASTER-Net observations report
  78. GRB 250807A: Enhanced Swift-XRT position
  79. IceCube-Cascade 250804A: Upper limits from a search for additional neutrino events in IceCube
  80. GRB 250807B: Swift detection of a burst with an optical counterpart.
  81. GRB 250805A: Kilonova-Catcher optical upper limits
  82. EP250806a:SVOM/VT refined analysis
  83. GRB 250805A: Swift/UVOT Upper Limits
  84. GRB 250806A: Swift/UVOT U-band detection
  85. EP250806a: Liverpool telescope optical upper limit
  86. GRB 250807A: Swift detection of a burst with an optical counterpart
  87. IceCube Alert 250804.84: Global MASTER-Net observations report
  88. GRB 250806A: EP-FXT observation
  89. EP#01709198415/EP250806a: Swift-XRT observations
  90. EP250806a: Global MASTER-Net observations report
  91. EP250802a: EP-FXT follow-up observation
  92. EP250806a: refined analysis of the EP-WXT and EP-FXT observations
  93. EP250806a: Earlier Detection of the VT Candidate by COLIBRÍ and LS
  94. EP250806a: SVOM /VT optical candidate
  95. GRB 250806A: J-band upper limit from WINTER
  96. GRB 250805A: Swift-BAT refined analysis
  97. GRB 250806A: KAIT optical upper limit
  98. GRB 250806A: SVOM/VT refined analysis
  99. GRB 250806A: Swift-XRT counterpart detection
  100. EP250806a: COLIBRÍ optical upper limit

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