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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"

19598 results found.

  1. IceCube-201209: No significant detection in HAWC
  2. Potential X-ray KN afterglow from Chandra observations of GW170817 ~3.3 years since merger (3 Epochs of 4)
  3. GRB 201214A: Swift ToO observations
  4. GRB 201203A: Zeiss-1000 (Koshka observatory) optical upper limit
  5. GRB 201203A: 1.3m DFOT, optical upper limits
  6. GRB 200826A: GMOS-N detected source magnitude (Correction)
  7. GRB 201015A: 5-GHz radio afterglow detection with the EVN
  8. GRB 201209A: Swift/UVOT Upper Limits
  9. Fermi-LAT Gamma-ray Observations of IceCube-201209A
  10. Chandra observations of GW170817 at ~3.3 years since merger (Observation 1 of 4)
  11. GRB 201208A: Swift-XRT afterglow detection
  12. IceCube-201209A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  13. GRB 201208A: LCO observations
  14. GRB 201209A: Xinglong-2.16m likely optical afterglow detection
  15. GRB 201209A: Enhanced Swift-XRT position
  16. GRB 201209A: Swift detection of a burst
  17. GRB 201208A: Swift ToO observations
  18. GRB 201208A: Fermi GBM Final Real-time Localization
  19. Fermi GRB 201207A: Global MASTER-Net observations report
  20. GRB 201203A: GROWTH-India Telescope optical upper limit.
  21. GRB 201203A: MITSuME Okayama optical upper limits
  22. GRB 201203A: Swift-XRT afterglow detection
  23. GRB 201203A: DDOTI Observations
  24. GRB 201203A: Swift detection of a burst
  25. IceCube-201130A: No significant detection in HAWC
  26. IceCube-201130A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  27. GRB 201128B: Swift-XRT observations
  28. Fermi-LAT Gamma-ray Observations of IceCube-201130A
  29. GRB 201201A: DDOTI Observations
  30. GRB 201128B: Swift ToO observations
  31. Swift-XRT observations of IceCube 201130A
  32. GRB 201128A: Swift/UVOT Upper Limits
  33. GRB 201130A: DDOTI Observations
  34. Baksan Neutrino Observatory Alert 201128.90: Global MASTER-Net observations report
  35. GRB 201128A: Enhanced Swift-XRT position
  36. GRB 201128A: DDOTI Observations
  37. GRB 201128A: Swift detection of a burst
  38. Fermi trigger No 628140709: DDOTI/OAN optical observations report
  39. AMON IC_HAWC NuEm-201124A: No Neutrino Counterpart detected with ANTARES
  40. IceCube-201120A in the Cygnus region: No enhanced TeV gamma-ray flux detected by HAWC
  41. GRB 200826A: TNG and LBT constraints on a supernova bump
  42. INTEGRAL Weak #8831 and #8832: AROMA-N Optical Observation
  43. Fermi-LAT Gamma-ray Observations of IceCube-201120A
  44. IceCube-201120A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  45. IceCube-201120A: Swift-XRT non-detection of 4FGL J2028.6+4110e
  46. GRB 201015A radio afterglow with e-MERLIN
  47. ZTF20acozryr/AT2020yxz (GRB 201103B): SAO RAS optical observations
  48. INTEGRAL Weak#8825: AROMA-N Optical Observation
  49. Fermi-LAT Gamma-ray Observations of IceCube-201114A
  50. GRB 201116A: Swift-XRT afterglow detection
  51. Swift Trigger 1006917 is Be/X-ray binary pulsar 1A 0535+262
  52. IceCube-201115A: No significant detection in HAWC
  53. IceCube-201114A: No significant detection in HAWC
  54. GRB 201116A: Tiled Swift observations
  55. IceCube-201115A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  56. IceCube-201114A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  57. INTEGRAL Weak#8811: AROMA-N Optical Observation
  58. Fermi-LAT Gamma-ray Observations of IceCube-201115A
  59. Swift XRT observations of the Fermi-LAT source 4FGL J0658.6+0636, positionally consistent with the IceCube high-energy neutrino alert
  60. Swift-XRT observations of IceCube 201114A
  61. Fermi-LAT Gamma-ray Observations of NuEm-201107A
  62. Swift Trigger 1005428: Detection of SGR 1830-0645
  63. ZTF20acozryr (GRB 201103B): GROWTH-India Telescope optical observations
  64. GRB 201104B: MITSuME Akeno optical observation
  65. GRB 201108A: Fermi GBM Final Real-time Localization
  66. GRB 201103B: GMG observation (2nd epoch)
  67. GRB201103B: GMG observation
  68. Swift XRT and UVOT detection of ZTF20acozryr/AT2020yxz/GRB201103B
  69. GRB 201104B: Kitab optical observations
  70. GRB 201103B (ZTF20acozryr/AT2020yxz): Xinglong-2.16m optical observations
  71. GRB 201104B: TSHAO optical observation
  72. GRB 201104B: Swift/UVOT Detection
  73. GRB 201104B: Swift-XRT refined Analysis
  74. GRB 201104C: Swift ToO observations
  75. IPN triangulation of GRB 201103B (consistent with ZTF20acozryr/AT2020yxz)
  76. ZTF20acozryr/AT2020yxz: Zwicky Transient Facility discovery of a fast optical transient with no associated GRB
  77. GRB 201104B: Swift-BAT refined analysis
  78. Swift Trigger 1004219: Detection of SGR 1830-0645
  79. GRB 201104A: Tiled Swift observations
  80. GRB 201104A: AGILE/MCAL detection
  81. GRB 201104B: Swift/UVOT Detection
  82. GRB 201104B: MASTER optical observation
  83. GRB 201104B: Swift detection of a burst
  84. GRB 201015A: Late X-ray Detections with Chandra
  85. GRB 201029A: Swift/UVOT Upper Limits
  86. GRB 201029A: BOOTES-1 optical upper limit
  87. GRB 201029A: Enhanced Swift-XRT position
  88. GRB 201029A: Swift detection of a burst
  89. GRB 201027A: MITSuME Akeno optical upper limits
  90. GRB 201027A: Swift/UVOT Upper Limits
  91. GRB 201026A: Swift/UVOT Upper Limits
  92. GRB 201027A: Enhanced Swift-XRT position
  93. GRB 201026A: Enhanced Swift-XRT position
  94. GRB 201020A: 1.3m DFOT, optical upper limits
  95. GRB 201027A: Swift detection of a burst
  96. GRB 201026A: NanShan/NEXT-0.6m optical upper limit
  97. GRB 201026A: Swift detection of a burst
  98. GRB 201024A: MITSuME Akeno optical upper limits
  99. GRB 201020B: HCT and GIT continued optical follow-up observations
  100. GRB 201024A: Swift/UVOT Detection

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