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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"

19670 results found.

  1. IPN triangulation of GRB 200111A
  2. LIGO/Virgo S200115j High Rank XRT sources are spurious
  3. GRB 200115A: MITSuME Okayama optical upper limits
  4. GRB 200115A: Nanshan-0.6m optical upper limit
  5. GRB 200115A: Swift detection of a burst
  6. Swift GRB200115.49: Global MASTER-Net observations report
  7. LIGO/Virgo S200114f: no counterpart candidates in the Swift/BAT observations
  8. LIGO/Virgo S200112r: Swift/BAT in the South Atlantic Anomaly
  9. GRB 200109A: Insight-HXMT/HE detection
  10. IceCube-200109A: Swift-XRT and UVoT Follow-up Observations
  11. ANTARES 200108A: No detection by Swift-XRT
  12. GRB 200107B: Swift/UVOT Observations
  13. GRB 200109A: Swift-BAT refined analysis
  14. Swift follow-up observations of IceCube-200107A: Identification of X-ray high state for 4FGL J0955.1+3551
  15. GRB 200109A: Swift/UVOT Upper Limits
  16. GRB 200109A: Fermi GBM observation
  17. GRB 200107B: Swift-XRT refined Analysis
  18. GRB 200109A: Swift-XRT refined Analysis
  19. GRB 200109A: Enhanced Swift-XRT position
  20. Swift GRB200109.07: Global MASTER-Net observations report
  21. GRB 200109A: Swift detection of a burst
  22. Swift GRB 200107B: Global MASTER-Net observations report
  23. GRB 200107B: Fermi GBM observation
  24. GRB 200107B: Swift-BAT refined analysis
  25. GRB 200107B: Swift detection of a burst
  26. Swift GRB200107.81: Global MASTER-Net OT detection
  27. Swift GRB200107.81: Global MASTER-Net observations report
  28. LIGO/Virgo S200105ae: no counterpart candidates in the Swift/BAT observations
  29. GRB 191228A: Early Optical Upper Limits from LCO
  30. GRB 191227A: Insight-HXMT/HE observation
  31. GRB 191221B: CALET Gamma-Ray Burst Monitor detection
  32. GRB 191228A: Mondy optical upper limit
  33. Konus-Wind observation of GRB 191227A
  34. IPN triangulation of GRB 191227B (short)
  35. GRB 191228A: Swift/UVOT Upper Limits
  36. GRB 191228A: Swift-XRT refined Analysis
  37. GRB 191227A: Swift-BAT refined analysis
  38. GRB 191228A: Swift-BAT refined analysis
  39. GRB 191228A: Enhanced Swift-XRT position
  40. GRB 191228A: Swift detection of a burst
  41. Swift GRB191228.00: Global MASTER-Net observations report
  42. GRB 191227A: Fermi GBM detection
  43. GRB 191227A: Marginal detection by Fermi-LAT
  44. Swift GRB191227A: Global MASTER-Net OT detection
  45. GRB 191227A: Swift detection of a burst
  46. Swift GRB191227.07: Global MASTER-Net observations report
  47. Swift Trigger 946234: further Swift analysis
  48. Swift GRB191226.25: Global MASTER-Net observations report
  49. Swift Triggers 946256 and 946257 are not a GRB
  50. Swift GRB191226.02: Global MASTER-Net observations report
  51. Swift Trigger 946234 is probably not a GRB
  52. Swift trigger 946234/GRB 191226.02 : MASTER obervation
  53. Konus-Wind observation of GRB 191221B
  54. GRB 191221B: Swift/UVOT Detection
  55. GRB 191221B: Insight-HXMT/HE detection
  56. GRB 191221B: AstroSat CZTI detection
  57. GRB 191221B: iTelescope optical observations
  58. GRB 191221B: Swift-BAT refined analysis
  59. GRB 191221B: Zadko observatory - Gingin optical observations
  60. GRB 191221B: LCO Optical Detection
  61. GRB 191221B: Swift-XRT refined Analysis
  62. LIGO/Virgo S191222n: no counterpart candidates in the Swift/BAT observations
  63. GRB 191221B: MASTER VWFC OT yearly detection
  64. GRB 191221B: VLT/X-shooter redshift
  65. GRB 191221B: Correction to GCN26551 - VIRT OT observation
  66. GRB 191221B: VIRT Optical Upper Limits
  67. GRB 191221B: AGILE/MCAL observations
  68. GRB 191221B: Enhanced Swift-XRT position
  69. GRB 191221B: Swift/UVOT redshift
  70. GRB 191221B: MASTER OT detection
  71. Swift GRB 191221B: Global MASTER-Net observations report
  72. GRB 191220A: Swift-BAT refined analysis
  73. GRB 191221B: Swift detection of a burst and a very bright optical candidate
  74. GRB 191220A: Swift/UVOT Upper Limits
  75. GRB 191220A: AbAO optical observations
  76. GRB 191220A: Swift-XRT refined Analysis
  77. GRB 191220A: Enhanced Swift-XRT position
  78. GRB 191220A: Swift detection of a burst
  79. GRB 191220A: Prompt enhanced Swift-XRT position
  80. Swift GRB191220.56: Global MASTER-Net observations report
  81. Konus-Wind observation of GRB 191218A
  82. LIGO/Virgo S191213g: Swift UVOT/XRT observations of Pan-STARRS1 candidate: PS19hgw
  83. LIGO/Virgo S191216ap, Swift XRT observations: 16 X-ray sources in the HAWC error region search
  84. GRB 191218A: Swift-BAT refined analysis
  85. Konus-Wind observation of GRB 191213A (ulong)
  86. GRB 191218A: AstroSat CZTI detection
  87. GRB 191218A: Swift detection of a burst
  88. LIGO/Virgo S191216ap and IceCube neutrino: Swift XRT sources
  89. LIGO/Virgo S191213g: Swift UVOT/XRT observations of three ZTF sources
  90. LIGO/Virgo S191216ap: no counterpart candidates in the Swift/BAT observations
  91. LIGO/Virgo S191215w: no counterpart candidates in the Swift/BAT observations
  92. GRB 191213A: BOOTES-5/JGT optical limit
  93. GRB 191213A: Swift-BAT refined analysis
  94. LIGO/Virgo S191213g: no counterpart candidates in the Swift/BAT observations
  95. GRB 191213A: Swift detection of a burst
  96. Possible HAWC-detected GRB 191210A: Swift-XRT observations
  97. LIGO/Virgo S191205ah: no counterpart candidates in the Swift/BAT observations
  98. LIGO/Virgo S191204r: no counterpart candidates in the Swift/BAT observations
  99. GRB 191130A: Swift-XRT observations
  100. GRB 191130A: Swift ToO observations

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