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"

32757 results found.

  1. GRB 050922C: break in the lightcurve
  2. GRB 050925: WSRT Radio Observations
  3. GRB050925: Swift UVOT upper limits
  4. Refined analysis of the Swift-BAT soft short burst
  5. GRB 050925 : I-band observation at Xinglong observatory
  6. GRB 050922B: Correction to BAT refined analysis, longer burst
  7. GRB050922C: TNG spectroscopic observations
  8. GRB050922B: refined XRT analysis
  9. Konus-Wind observation of GRB 050922C
  10. GRB 050922C: Refined redshift
  11. GRB050922B: Swift UVOT early upper limits.
  12. GRB OT observation
  13. GRB050922C: observation at MonteBoo
  14. INT 2.5m limit for GRB050922B
  15. GRB 050922B: optical limit
  16. GRB050922C: Optical Observations
  17. GRB 050922C: Swift XRT refined analysis
  18. HETE Fregate observations of GRB 050922C
  19. GRB 050922C: Swift-BAT refined analysis
  20. GRB 050922B: Swift-BAT refined analysis
  21. GRB050922C: optical observations
  22. GRB 050922C: Absorption redshift from the Nordic Optical Telescope
  23. GRB 050922C: NOT optical observations
  24. GRB 050922A: Analysis of Swift/XRT TOO observation
  25. GRB 050922C: Swift detection of a bright burst
  26. GRB 050922C: ROTSE-IIId Refined Analysis
  27. GRB 050922C: ROTSE-III Detection of Possible Counterpart
  28. GRB 050922B: ROTSE-III Optical Limits
  29. GRB050918: Possible Swift/XRT detected afterglow
  30. GRB050916: Swift/UVOT Upper Limits
  31. GRB 050916: Swift-BAT refined analysis
  32. GRB 050915a: Radio Observations
  33. Swift-BAT trigger 155764 is not a GRB
  34. Swift-BAT trigger 155764 is probably not a GRB
  35. GRB050916 : Swift-XRT refined analysis
  36. GRB 050916: XRT position
  37. GRB 050915b, SMARTS optical/IR observations of the XRT position
  38. GRB 050915B: Swift-BAT refined analysis
  39. GRB 050915B: Swift/UVOT Upper Limits
  40. GRB 050915a: IR Transient
  41. GRB 050915B: XRT position
  42. GRB 050915b, SMARTS optical/IR observations
  43. GRB050915: Swift/UVOT upper limits
  44. GRB 050915: KAIT optical limit
  45. GRB 050915: IR Observations
  46. GRB 050915: Swift XRT refined analysis
  47. GRB 050915: Swift-BAT refined analysis
  48. GRB050915: P60 Optical Observations
  49. GRB050915, optical observations
  50. GRB050915: XRT position
  51. GRB 050915: ROTSE-III optical limits
  52. GRB050911: Upper limit on X-ray afterglow
  53. Swift-BAT trigger 155072 ground analysis
  54. Swift-BAT trigger 155072 is probably not a GRB
  55. GRB 050911: LCO limits on a variable source
  56. GRB 050908: DEIMOS spectrum and further analysis
  57. Swift is in normal operation
  58. GRB050911: Swift UVOT followup observations
  59. GRB050911: Swift-XRT position
  60. GRB 050911: LCO observations
  61. GRB 050911, optical observations
  62. GRB 050911: Swift-BAT refined analysis
  63. GRB 050911: z~0.16 cluster in the field
  64. GRB050908: detection of Swift/UVOT optical counterpart
  65. GRB 050910a: TAROT early optical limits
  66. RBO GRB 050908 observations
  67. WIRO observations in I of GRB 050908
  68. GRB 050906: Possible X-ray Counterpart
  69. GRB 050906: RTT150 optical observations
  70. GRB050908: Swift/UVOT Early upper limits
  71. GRB050908: VLT R-band decay index.
  72. GRB 050908: Swift-BAT refined analysis
  73. GRB 050908: Optical observations
  74. Gemini Spectroscopy of GRB 050908
  75. GRB 050908: spectroscopic redshift
  76. GRB 050908: Prompt PROMPT Observations
  77. GRB 050908 : Swift XRT position
  78. GRB 050908: KAIT observations
  79. GRB 050908: P60 Confirmation of Optical Afterglow
  80. GRB 050908: Optical Observations
  81. GRB 050906: Optical observations at the Very Large Telescope
  82. GRB050904: CrAO optical observations
  83. GRB 050904 BAT refined analysis of complete data set
  84. GRB 050904: Subaru Optical Spectroscopy
  85. GRB 050906: MARGE Optical Limits
  86. GRB 050906: Swift-BAT refined analysis
  87. GRB 050906: Swift XRT upper limit
  88. GRB 050906: Radio Observations
  89. GRB 050904: Keck I-band Imaging
  90. GRB050906: P60 Observations
  91. GRB 050904: more VLT NIR observations
  92. GRB 050904: BOOTES early R-band observation
  93. GRB 050906: Bright galaxy in BAT error box
  94. GRB 050906: Swift/BAT Detection of a possible burst
  95. GRB 050904: More SOAR
  96. GRB 050904: photometric redshift
  97. GRB 050904: Swift/UVOT observations
  98. GRB 050904: Afterglow Astrometry
  99. GRB 050904: NIR object inside the XRT error box
  100. GRB 050904: early Swift XRT analysis results

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