Skip to main content
Circulars over Kafka event name backfill. See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"
  1. GRB 060904B: Swift-BAT refined analysis
  2. GRB060904b: Optical observations with Swift/UVOT
  3. Konus-Wind observation of GRB 060904A
  4. GRB 060904B: Swift-XRT refined analysis
  5. GRB 060904A: Refined analysis of the Swift-BAT burst
  6. GRB 060904A: Swift-XRT refined analysis
  7. GRB 060904A: Suzaku-XIS and -HXD observation plan
  8. GRB 060904B: VLT redshift
  9. GRB 060904A: P60 Observations
  10. GRB 060904B: Optical observations at Crni Vrh
  11. GRB060904B: Watcher observations
  12. GRB 060904B BOOTES-IR and 1.5m OSN observations
  13. GRB 060904B: TAROT optical counterpart observations
  14. GRB060904B - SDSS Pre-Burst Observations
  15. GRB 060904: TAROT optical observations
  16. GRB 060904B: Swift detection of a burst with optical counterpart
  17. GRB 060904B: ROTSE-III Detection of Optical Counterpart
  18. GRB060904 - SDSS Pre-Burst Observations
  19. GRB 060904: Swift detection of a bright burst
  20. GRB060901: Optical observations
  21. 060901: Swift UVOT followup observations
  22. GRB 060901: pseudo-z from spectral parameters of the prompt
  23. Konus-Wind observation of GRB 060901
  24. GRB 060901: SMARTS optical/IR observations update
  25. GRB 060901: Swift/XRT Refined Analysis
  26. GRB 060901: SMARTS optical/IR observations
  27. GRB 060901: Swift/XRT Position
  28. GRB 060901: further INTEGRAL results
  29. GRB 060901: Watcher observations
  30. GRB 060901: a long GRB detected by INTEGRAL
  31. Two bright bursts from SGR 1806-20 detected with IBAS
  32. GRB 060605, observations using an Integral Field Unit
  33. GRB 060604: VLA Observation
  34. GRB 060814: Suzaku/WAM observation of the prompt emission
  35. GRB 060605: VLA Observation
  36. GRB 060707: VLA observation
  37. GRB 060825: VLA observations
  38. GRB 060825: pseudo-z from spectral parameters of the prompt emission
  39. Swift-BAT trigger 226614 is not a GRB
  40. GRB060826 - SDSS Pre-Burst Observations
  41. GRB 060826(?): Swift detection of a possible burst
  42. GRB 060825: XRT Team Refined Analysis
  43. GRB 060825: Swift-BAT Refined Analysis
  44. GRB 060813: Swift/BAT, Konus-Wind, and Suzaku/WAM joint prompt spectral analysis
  45. GRB060825: Liverpool Telescope optical observations
  46. GRB 060825: TNG optical observations
  47. GRB 060825: TAROT optical observations
  48. GRB 060825: P60 Observations
  49. GRB060825: BOOTES-IR optical observations
  50. GRB 060825: Swift detection of a burst
  51. GRB060801: host galaxy redshift
  52. GRB060729: analysis of XMM-Newton observation
  53. GRB 060814: pseudo-z from spectral parameters of the prompt
  54. IBAS Alerts No 3429 and 3430: not GRBs
  55. Radio observations of GRB 060719
  56. GRB 060729, SMARTS optical/IR observations
  57. GRB060814: Break in the XRT light curve
  58. GRB060813: Break in the XRT light curve
  59. GRB 060813: A long, bright GRB detected with Suzaku WAM
  60. GRB 060814: Confirmation of IR afterglow
  61. Konus-Wind observation of GRB 060814
  62. GRB 060814: Refined analysis of the Swift-BAT burst
  63. GRB 060814: P60 Observations
  64. GRB 060814: P200 NIR Observations
  65. GRB 060814: source inside revised XRT error box
  66. GRB 060814: Possible IR counterpart
  67. GRB060805B: optical observations
  68. GRB060814: Swift/UVOT upper limits
  69. GRB 060813: pseudo-z from spectral parameters of the prompt
  70. GRB 060814: Swift XRT refined analysis
  71. GRB 060814: VLT optical limits
  72. GRB 060814 - SDSS Pre-Burst Observations
  73. GRB 060814: TAROT optical observations
  74. GRB 060814: Swift detection of a bright burst
  75. Konus-Wind observation of GRB 060813
  76. GRB060813: Swift/UVOT upper limits
  77. GRB 060813: Swift XRT refined analysis
  78. GRB 060813: Refined analysis of the Swift-BAT burst
  79. GRB 060813: Swift detection of a burst
  80. GRB051109B: Late-time Radio Observations
  81. Image of the dust-scattering halo around SGR 1806-20
  82. Second VLA limit on new radio point source in SGR 1806-20
  83. A dust-scattering halo detected around SGR 1806-20
  84. GRB 060805B: pseudo-z from spectral parameters of the prompt emission
  85. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  86. GRB060807: Possible Highly Significant X-ray Emission Lines
  87. GRB060714: optical observations
  88. IBAS Alert n. 3422: not a GRB
  89. GRB 060729: An update on the Swift XRT and UVOT observations
  90. GRB060717: optical observations
  91. GRB060807: Optical limiting magnitudes
  92. GRB 060805B: optical observation at Sierra Nevada
  93. GRB 060805B: XRT Team Analysis
  94. VLA Upper Limit on Outburst of SGR 1806-20
  95. GRB060806 is similar to previous activity of SGR1806-20
  96. GRB 060807: UVOT Upper limits
  97. GRB 060807: afterglow confirmation
  98. GRB 060807: XRT Team refined analysis
  99. GRB 060807: K- and R-band observations
  100. GRB 060807: Refined analysis of the Swift-BAT burst

Advanced

Download all Circulars as a .tar.gz archive:
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