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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.

Advanced Search Examples (click to copy):

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

19684 results found.

  1. GRB 201209A: Enhanced Swift-XRT position
  2. GRB 201209A: Swift detection of a burst
  3. GRB 201208A: Swift ToO observations
  4. GRB 201208A: Fermi GBM Final Real-time Localization
  5. Fermi GRB 201207A: Global MASTER-Net observations report
  6. GRB 201203A: GROWTH-India Telescope optical upper limit.
  7. GRB 201203A: MITSuME Okayama optical upper limits
  8. GRB 201203A: Swift-XRT afterglow detection
  9. GRB 201203A: DDOTI Observations
  10. GRB 201203A: Swift detection of a burst
  11. IceCube-201130A: No significant detection in HAWC
  12. IceCube-201130A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  13. GRB 201128B: Swift-XRT observations
  14. Fermi-LAT Gamma-ray Observations of IceCube-201130A
  15. GRB 201201A: DDOTI Observations
  16. GRB 201128B: Swift ToO observations
  17. Swift-XRT observations of IceCube 201130A
  18. GRB 201128A: Swift/UVOT Upper Limits
  19. GRB 201130A: DDOTI Observations
  20. Baksan Neutrino Observatory Alert 201128.90: Global MASTER-Net observations report
  21. GRB 201128A: Enhanced Swift-XRT position
  22. GRB 201128A: DDOTI Observations
  23. GRB 201128A: Swift detection of a burst
  24. Fermi trigger No 628140709: DDOTI/OAN optical observations report
  25. AMON IC_HAWC NuEm-201124A: No Neutrino Counterpart detected with ANTARES
  26. IceCube-201120A in the Cygnus region: No enhanced TeV gamma-ray flux detected by HAWC
  27. GRB 200826A: TNG and LBT constraints on a supernova bump
  28. INTEGRAL Weak #8831 and #8832: AROMA-N Optical Observation
  29. Fermi-LAT Gamma-ray Observations of IceCube-201120A
  30. IceCube-201120A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  31. IceCube-201120A: Swift-XRT non-detection of 4FGL J2028.6+4110e
  32. GRB 201015A radio afterglow with e-MERLIN
  33. ZTF20acozryr/AT2020yxz (GRB 201103B): SAO RAS optical observations
  34. INTEGRAL Weak#8825: AROMA-N Optical Observation
  35. Fermi-LAT Gamma-ray Observations of IceCube-201114A
  36. GRB 201116A: Swift-XRT afterglow detection
  37. Swift Trigger 1006917 is Be/X-ray binary pulsar 1A 0535+262
  38. IceCube-201115A: No significant detection in HAWC
  39. IceCube-201114A: No significant detection in HAWC
  40. GRB 201116A: Tiled Swift observations
  41. IceCube-201115A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  42. IceCube-201114A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  43. INTEGRAL Weak#8811: AROMA-N Optical Observation
  44. Fermi-LAT Gamma-ray Observations of IceCube-201115A
  45. Swift XRT observations of the Fermi-LAT source 4FGL J0658.6+0636, positionally consistent with the IceCube high-energy neutrino alert
  46. Swift-XRT observations of IceCube 201114A
  47. Fermi-LAT Gamma-ray Observations of NuEm-201107A
  48. Swift Trigger 1005428: Detection of SGR 1830-0645
  49. ZTF20acozryr (GRB 201103B): GROWTH-India Telescope optical observations
  50. GRB 201104B: MITSuME Akeno optical observation
  51. GRB 201108A: Fermi GBM Final Real-time Localization
  52. GRB 201103B: GMG observation (2nd epoch)
  53. GRB201103B: GMG observation
  54. Swift XRT and UVOT detection of ZTF20acozryr/AT2020yxz/GRB201103B
  55. GRB 201104B: Kitab optical observations
  56. GRB 201103B (ZTF20acozryr/AT2020yxz): Xinglong-2.16m optical observations
  57. GRB 201104B: TSHAO optical observation
  58. GRB 201104B: Swift/UVOT Detection
  59. GRB 201104B: Swift-XRT refined Analysis
  60. GRB 201104C: Swift ToO observations
  61. IPN triangulation of GRB 201103B (consistent with ZTF20acozryr/AT2020yxz)
  62. ZTF20acozryr/AT2020yxz: Zwicky Transient Facility discovery of a fast optical transient with no associated GRB
  63. GRB 201104B: Swift-BAT refined analysis
  64. Swift Trigger 1004219: Detection of SGR 1830-0645
  65. GRB 201104A: Tiled Swift observations
  66. GRB 201104A: AGILE/MCAL detection
  67. GRB 201104B: Swift/UVOT Detection
  68. GRB 201104B: MASTER optical observation
  69. GRB 201104B: Swift detection of a burst
  70. GRB 201015A: Late X-ray Detections with Chandra
  71. GRB 201029A: Swift/UVOT Upper Limits
  72. GRB 201029A: BOOTES-1 optical upper limit
  73. GRB 201029A: Enhanced Swift-XRT position
  74. GRB 201029A: Swift detection of a burst
  75. GRB 201027A: MITSuME Akeno optical upper limits
  76. GRB 201027A: Swift/UVOT Upper Limits
  77. GRB 201026A: Swift/UVOT Upper Limits
  78. GRB 201027A: Enhanced Swift-XRT position
  79. GRB 201026A: Enhanced Swift-XRT position
  80. GRB 201020A: 1.3m DFOT, optical upper limits
  81. GRB 201027A: Swift detection of a burst
  82. GRB 201026A: NanShan/NEXT-0.6m optical upper limit
  83. GRB 201026A: Swift detection of a burst
  84. GRB 201024A: MITSuME Akeno optical upper limits
  85. GRB 201020B: HCT and GIT continued optical follow-up observations
  86. GRB 201024A: Swift/UVOT Detection
  87. GRB 201020B: follow-up observations with Savelli Telescope
  88. GRB 201024A: VIRT optical observations
  89. GRB 201024A: Enhanced Swift-XRT position
  90. GRB 201020B: Redshift from GTC/OSIRIS
  91. GRB 201024A: Redshift from GTC/OSIRIS
  92. GRB 201024A: Swift detection of a burst with an optical afterglow
  93. IceCube-201021A: No significant detection in HAWC
  94. IceCube-201021A: Optical counterpart of WISEA J172314.13+142101.5
  95. GRB 201020B: GROWTH-India Telescope optical observations
  96. Fermi-LAT Gamma-ray Observations of IceCube-201021A and detection of a new gamma-ray source, Fermi J1725.5+1312
  97. GRB 201020B: Konkoly Obs. optical detection
  98. Swift-XRT observations of IceCube 201021A (2)
  99. GRB 201020A: GROWTH-India Telescope late-time optical upper limit
  100. GRB 201021C: Swift/UVOT Detection

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