Skip to main content
Retirement of GCN Classic VOEvent Brokers. 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 060904A Milagro GeV/TeV Observations
  2. GRB060904b, optical observations
  3. GRB 060904b: SMARTS optical/IR afterglow observations
  4. GRB 060904B: RTT150 optical observations
  5. GRB060904A: Swift/UVOT optical observations
  6. GRB 060904A: Subaru NIR observation
  7. GRB 060904A: pseudo-z from spectral parameters of the prompt emission
  8. GRB 060904B: Swift-BAT refined analysis
  9. GRB060904b: Optical observations with Swift/UVOT
  10. Konus-Wind observation of GRB 060904A
  11. GRB 060904B: Swift-XRT refined analysis
  12. GRB 060904A: Refined analysis of the Swift-BAT burst
  13. GRB 060904A: Swift-XRT refined analysis
  14. GRB 060904A: Suzaku-XIS and -HXD observation plan
  15. GRB 060904B: VLT redshift
  16. GRB 060904A: P60 Observations
  17. GRB 060904B: Optical observations at Crni Vrh
  18. GRB060904B: Watcher observations
  19. GRB 060904B BOOTES-IR and 1.5m OSN observations
  20. GRB 060904B: TAROT optical counterpart observations
  21. GRB060904B - SDSS Pre-Burst Observations
  22. GRB 060904: TAROT optical observations
  23. GRB 060904B: Swift detection of a burst with optical counterpart
  24. GRB 060904B: ROTSE-III Detection of Optical Counterpart
  25. GRB060904 - SDSS Pre-Burst Observations
  26. GRB 060904: Swift detection of a bright burst
  27. GRB060901: Optical observations
  28. 060901: Swift UVOT followup observations
  29. GRB 060901: pseudo-z from spectral parameters of the prompt
  30. Konus-Wind observation of GRB 060901
  31. GRB 060901: SMARTS optical/IR observations update
  32. GRB 060901: Swift/XRT Refined Analysis
  33. GRB 060901: SMARTS optical/IR observations
  34. GRB 060901: Swift/XRT Position
  35. GRB 060901: further INTEGRAL results
  36. GRB 060901: Watcher observations
  37. GRB 060901: a long GRB detected by INTEGRAL
  38. Two bright bursts from SGR 1806-20 detected with IBAS
  39. GRB 060605, observations using an Integral Field Unit
  40. GRB 060604: VLA Observation
  41. GRB 060814: Suzaku/WAM observation of the prompt emission
  42. GRB 060605: VLA Observation
  43. GRB 060707: VLA observation
  44. GRB 060825: VLA observations
  45. GRB 060825: pseudo-z from spectral parameters of the prompt emission
  46. Swift-BAT trigger 226614 is not a GRB
  47. GRB060826 - SDSS Pre-Burst Observations
  48. GRB 060826(?): Swift detection of a possible burst
  49. GRB 060825: XRT Team Refined Analysis
  50. GRB 060825: Swift-BAT Refined Analysis
  51. GRB 060813: Swift/BAT, Konus-Wind, and Suzaku/WAM joint prompt spectral analysis
  52. GRB060825: Liverpool Telescope optical observations
  53. GRB 060825: TNG optical observations
  54. GRB 060825: TAROT optical observations
  55. GRB 060825: P60 Observations
  56. GRB060825: BOOTES-IR optical observations
  57. GRB 060825: Swift detection of a burst
  58. GRB060801: host galaxy redshift
  59. GRB060729: analysis of XMM-Newton observation
  60. GRB 060814: pseudo-z from spectral parameters of the prompt
  61. IBAS Alerts No 3429 and 3430: not GRBs
  62. Radio observations of GRB 060719
  63. GRB 060729, SMARTS optical/IR observations
  64. GRB060814: Break in the XRT light curve
  65. GRB060813: Break in the XRT light curve
  66. GRB 060813: A long, bright GRB detected with Suzaku WAM
  67. GRB 060814: Confirmation of IR afterglow
  68. Konus-Wind observation of GRB 060814
  69. GRB 060814: Refined analysis of the Swift-BAT burst
  70. GRB 060814: P60 Observations
  71. GRB 060814: P200 NIR Observations
  72. GRB 060814: source inside revised XRT error box
  73. GRB 060814: Possible IR counterpart
  74. GRB060805B: optical observations
  75. GRB060814: Swift/UVOT upper limits
  76. GRB 060813: pseudo-z from spectral parameters of the prompt
  77. GRB 060814: Swift XRT refined analysis
  78. GRB 060814: VLT optical limits
  79. GRB 060814 - SDSS Pre-Burst Observations
  80. GRB 060814: TAROT optical observations
  81. GRB 060814: Swift detection of a bright burst
  82. Konus-Wind observation of GRB 060813
  83. GRB060813: Swift/UVOT upper limits
  84. GRB 060813: Swift XRT refined analysis
  85. GRB 060813: Refined analysis of the Swift-BAT burst
  86. GRB 060813: Swift detection of a burst
  87. GRB051109B: Late-time Radio Observations
  88. Image of the dust-scattering halo around SGR 1806-20
  89. Second VLA limit on new radio point source in SGR 1806-20
  90. A dust-scattering halo detected around SGR 1806-20
  91. GRB 060805B: pseudo-z from spectral parameters of the prompt emission
  92. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  93. GRB060807: Possible Highly Significant X-ray Emission Lines
  94. GRB060714: optical observations
  95. IBAS Alert n. 3422: not a GRB
  96. GRB 060729: An update on the Swift XRT and UVOT observations
  97. GRB060717: optical observations
  98. GRB060807: Optical limiting magnitudes
  99. GRB 060805B: optical observation at Sierra Nevada
  100. GRB 060805B: XRT Team Analysis

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