Skip to main content
New! BOOM Notices and Schema v7.0.0. 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. Konus-Wind observation of GRB 060813
  2. GRB060813: Swift/UVOT upper limits
  3. GRB 060813: Swift XRT refined analysis
  4. GRB 060813: Refined analysis of the Swift-BAT burst
  5. GRB 060813: Swift detection of a burst
  6. GRB051109B: Late-time Radio Observations
  7. Image of the dust-scattering halo around SGR 1806-20
  8. Second VLA limit on new radio point source in SGR 1806-20
  9. A dust-scattering halo detected around SGR 1806-20
  10. GRB 060805B: pseudo-z from spectral parameters of the prompt emission
  11. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  12. GRB060807: Possible Highly Significant X-ray Emission Lines
  13. GRB060714: optical observations
  14. IBAS Alert n. 3422: not a GRB
  15. GRB 060729: An update on the Swift XRT and UVOT observations
  16. GRB060717: optical observations
  17. GRB060807: Optical limiting magnitudes
  18. GRB 060805B: optical observation at Sierra Nevada
  19. GRB 060805B: XRT Team Analysis
  20. VLA Upper Limit on Outburst of SGR 1806-20
  21. GRB060806 is similar to previous activity of SGR1806-20
  22. GRB 060807: UVOT Upper limits
  23. GRB 060807: afterglow confirmation
  24. GRB 060807: XRT Team refined analysis
  25. GRB 060807: K- and R-band observations
  26. GRB 060807: Refined analysis of the Swift-BAT burst
  27. GRB060807: optical afterglow candidate
  28. GRB060806 = SGR1806-20
  29. GRB 060805B: RHESSI Spectral Fit
  30. GRB060807: optical upper limit in white light
  31. IPN triangulation of GRB060806 (long, exceptionally bright)
  32. GRB060807 - SDSS Pre-burst Observations
  33. GRB 060805B: X-ray Afterglow Detection, Spectral/Spatial/Temporal Properties
  34. GRB 060805B: Swift/UVOT Upper Limits
  35. GRB 060807, optical observation
  36. GRB 060807: Kanazawa R-band observation
  37. GRB 060807: optical limit
  38. GRB 060807: Swift detection of a burst
  39. GRB 060801: Second Epoch WSRT Radio Observations
  40. IPN triangulation of GRB060805B
  41. GRB060805 Liverpool Telescope observations
  42. GRB 060805: optical upper limit in R
  43. GRB 060805: XRT Team Refined Analysis
  44. GRB 060805: Swift-BAT Refined Analysis
  45. GRB 060805: Swift/UVOT Upper Limits
  46. GRB 060805: P60 Observations
  47. GRB 060805: KAIT observations
  48. GRB 060805 - SDSS Pre-Burst Observations
  49. GRB 060805: Swift detection of a burst
  50. GRB 060804: Swift UVOT observations
  51. GRB 060804: Swift-XRT Team Refined Analysis
  52. GRB 060804: Refined analysis of the Swift-BAT burst
  53. GRB 060804: Swift detection of a burst with a possible UVOT counterpart
  54. GRB 060728: Upper limits of the X-ray emission
  55. GRB 060801: no variability of optical sources
  56. IBAS Alert 3418: not a GRB
  57. GRB 060801: WSRT Radio Observations
  58. GRB 060801: XRT/SDSS Frame Offset and Refined XRT Position
  59. GRB060801: Radio Observations
  60. GRB 051109B: Bright spiral host galaxy at low redshift
  61. GRB 060801: optical observations at FORS2/VLT
  62. GRB060801: Swift/UVOT Upper Limits
  63. GRB 060801: optical observations at Hanle and Calar Alto
  64. GRB060801: optical upper limit in R
  65. GRB 060801: Swift XRT refined analysis
  66. GRB 060801: Refined analysis of the Swift-BAT short hard burst
  67. GRB 060801, optical observation
  68. GRB 060801: Kanazawa Optical Observation
  69. GRB 060801: Swift detection of a short burst
  70. GRB060729: ROTSE-III Observations of the Slow Optical Decay
  71. GRB 060218 / SN 2006aj Nebular Spectrum
  72. IBAS Alert n. 3415: not a GRB
  73. Swift-BAT trigger 221873 is not a GRB or a Transient
  74. GRB 060729 redshift
  75. GRB 060719: TORTOREM optical upper limits
  76. GRB 060729: Swift/UVOT Detections
  77. GRB 060729: Refined analysis of the Swift-BAT burst
  78. GRB 060729: Swift-XRT refined analysis
  79. GRB 060729 : Planned XMM-Newton observation
  80. GRB 060729: Swift/UVOT Observations
  81. GRB 060729: ROTSE-III Detection of Optical Counterpart
  82. GRB 060729: Swift detection of a burst with an UVOT optical counterpart
  83. GRB 060728: Swift/UVOT Upper Limits
  84. GRB 060728: Refined analysis of the Swift-BAT burst
  85. GRB 060728, SMARTS optical/IR observations
  86. Swift/XRT preliminary analysis
  87. GRB 060728: Swift detection of a burst
  88. GRB060614 ATCA Radio Limits
  89. GRB 060218 (SN 2006aj): IR afterglow detection six months after the
  90. GRB 060714: Swift/UVOT Observations
  91. GRB060719: prompt NIR observations with REM
  92. GRB 060714: NOT observations
  93. GRB 060719: near-infrared afterglow
  94. GRB 060719: correction to the coordinates reported in GCN 5347
  95. GRB 060522: VLA observation
  96. GRB 060719: Swift/UVOT Upper Limits
  97. GRB 060719: VLT/ISAAC observations
  98. GRB 060719: Refined analysis of the Swift-BAT burst
  99. GRB 060719: XRT refined analysis
  100. GRB 060719: further analysis of VLT observations

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