Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. See news and announcements

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"

19663 results found.

  1. GRB 200115A: Nanshan-0.6m optical upper limit
  2. GRB 200115A: Swift detection of a burst
  3. Swift GRB200115.49: Global MASTER-Net observations report
  4. LIGO/Virgo S200114f: no counterpart candidates in the Swift/BAT observations
  5. LIGO/Virgo S200112r: Swift/BAT in the South Atlantic Anomaly
  6. GRB 200109A: Insight-HXMT/HE detection
  7. IceCube-200109A: Swift-XRT and UVoT Follow-up Observations
  8. ANTARES 200108A: No detection by Swift-XRT
  9. GRB 200107B: Swift/UVOT Observations
  10. GRB 200109A: Swift-BAT refined analysis
  11. Swift follow-up observations of IceCube-200107A: Identification of X-ray high state for 4FGL J0955.1+3551
  12. GRB 200109A: Swift/UVOT Upper Limits
  13. GRB 200109A: Fermi GBM observation
  14. GRB 200107B: Swift-XRT refined Analysis
  15. GRB 200109A: Swift-XRT refined Analysis
  16. GRB 200109A: Enhanced Swift-XRT position
  17. Swift GRB200109.07: Global MASTER-Net observations report
  18. GRB 200109A: Swift detection of a burst
  19. Swift GRB 200107B: Global MASTER-Net observations report
  20. GRB 200107B: Fermi GBM observation
  21. GRB 200107B: Swift-BAT refined analysis
  22. GRB 200107B: Swift detection of a burst
  23. Swift GRB200107.81: Global MASTER-Net OT detection
  24. Swift GRB200107.81: Global MASTER-Net observations report
  25. LIGO/Virgo S200105ae: no counterpart candidates in the Swift/BAT observations
  26. GRB 191228A: Early Optical Upper Limits from LCO
  27. GRB 191227A: Insight-HXMT/HE observation
  28. GRB 191221B: CALET Gamma-Ray Burst Monitor detection
  29. GRB 191228A: Mondy optical upper limit
  30. Konus-Wind observation of GRB 191227A
  31. IPN triangulation of GRB 191227B (short)
  32. GRB 191228A: Swift/UVOT Upper Limits
  33. GRB 191228A: Swift-XRT refined Analysis
  34. GRB 191227A: Swift-BAT refined analysis
  35. GRB 191228A: Swift-BAT refined analysis
  36. GRB 191228A: Enhanced Swift-XRT position
  37. GRB 191228A: Swift detection of a burst
  38. Swift GRB191228.00: Global MASTER-Net observations report
  39. GRB 191227A: Fermi GBM detection
  40. GRB 191227A: Marginal detection by Fermi-LAT
  41. Swift GRB191227A: Global MASTER-Net OT detection
  42. GRB 191227A: Swift detection of a burst
  43. Swift GRB191227.07: Global MASTER-Net observations report
  44. Swift Trigger 946234: further Swift analysis
  45. Swift GRB191226.25: Global MASTER-Net observations report
  46. Swift Triggers 946256 and 946257 are not a GRB
  47. Swift GRB191226.02: Global MASTER-Net observations report
  48. Swift Trigger 946234 is probably not a GRB
  49. Swift trigger 946234/GRB 191226.02 : MASTER obervation
  50. Konus-Wind observation of GRB 191221B
  51. GRB 191221B: Swift/UVOT Detection
  52. GRB 191221B: Insight-HXMT/HE detection
  53. GRB 191221B: AstroSat CZTI detection
  54. GRB 191221B: iTelescope optical observations
  55. GRB 191221B: Swift-BAT refined analysis
  56. GRB 191221B: Zadko observatory - Gingin optical observations
  57. GRB 191221B: LCO Optical Detection
  58. GRB 191221B: Swift-XRT refined Analysis
  59. LIGO/Virgo S191222n: no counterpart candidates in the Swift/BAT observations
  60. GRB 191221B: MASTER VWFC OT yearly detection
  61. GRB 191221B: VLT/X-shooter redshift
  62. GRB 191221B: Correction to GCN26551 - VIRT OT observation
  63. GRB 191221B: VIRT Optical Upper Limits
  64. GRB 191221B: AGILE/MCAL observations
  65. GRB 191221B: Enhanced Swift-XRT position
  66. GRB 191221B: Swift/UVOT redshift
  67. GRB 191221B: MASTER OT detection
  68. Swift GRB 191221B: Global MASTER-Net observations report
  69. GRB 191220A: Swift-BAT refined analysis
  70. GRB 191221B: Swift detection of a burst and a very bright optical candidate
  71. GRB 191220A: Swift/UVOT Upper Limits
  72. GRB 191220A: AbAO optical observations
  73. GRB 191220A: Swift-XRT refined Analysis
  74. GRB 191220A: Enhanced Swift-XRT position
  75. GRB 191220A: Swift detection of a burst
  76. GRB 191220A: Prompt enhanced Swift-XRT position
  77. Swift GRB191220.56: Global MASTER-Net observations report
  78. Konus-Wind observation of GRB 191218A
  79. LIGO/Virgo S191213g: Swift UVOT/XRT observations of Pan-STARRS1 candidate: PS19hgw
  80. LIGO/Virgo S191216ap, Swift XRT observations: 16 X-ray sources in the HAWC error region search
  81. GRB 191218A: Swift-BAT refined analysis
  82. Konus-Wind observation of GRB 191213A (ulong)
  83. GRB 191218A: AstroSat CZTI detection
  84. GRB 191218A: Swift detection of a burst
  85. LIGO/Virgo S191216ap and IceCube neutrino: Swift XRT sources
  86. LIGO/Virgo S191213g: Swift UVOT/XRT observations of three ZTF sources
  87. LIGO/Virgo S191216ap: no counterpart candidates in the Swift/BAT observations
  88. LIGO/Virgo S191215w: no counterpart candidates in the Swift/BAT observations
  89. GRB 191213A: BOOTES-5/JGT optical limit
  90. GRB 191213A: Swift-BAT refined analysis
  91. LIGO/Virgo S191213g: no counterpart candidates in the Swift/BAT observations
  92. GRB 191213A: Swift detection of a burst
  93. Possible HAWC-detected GRB 191210A: Swift-XRT observations
  94. LIGO/Virgo S191205ah: no counterpart candidates in the Swift/BAT observations
  95. LIGO/Virgo S191204r: no counterpart candidates in the Swift/BAT observations
  96. GRB 191130A: Swift-XRT observations
  97. GRB 191130A: Swift ToO observations
  98. GRB 191130A, a long burst detected in Swift-BAT ground analysis
  99. GRB 191004A: correction to reported GROND upper limits
  100. LIGO/Virgo S191129u: Swift/BAT in SAA

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov