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. BeppoSAX/GRBM detection of GRB 010801
  2. GCN and HETE status
  3. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  4. BeppoSAX/GRBM detection of GRB010728
  5. GRB 010222 - WHT BVRI images
  6. SGR1900+14 burst seen by HETE: BeppoSAX data
  7. GRB 010629 Optical Observations
  8. GRB010629: Optical Observations
  9. SGR1900+14: High Fluence Burst Localized by HETE
  10. GRB010629, optical observations
  11. IPN triangulation of GRB010629
  12. GRB010629: A Burst Localized by HETE
  13. SGR1900+14: Second Burst Localized by HETE
  14. SGR1900+14: A Burst Localized by HETE
  15. Possible burst from SGR1806-20
  16. IPN detection of SGR1900+14
  17. SGR1806-20: A Second, Intense Burst Localized by HETE
  18. GRB 00630: Host Galaxy
  19. SGR1806-20: Localization by HETE
  20. IPN triangulation of GRB010613
  21. IPN triangulation of GRB010612
  22. IPN triangulation of GRB010612
  23. HETE Fully-Automated GCN Notices
  24. GRB000301C: Late-time HST/STIS observation
  25. GRB010518: a faint BeppoSAX detection
  26. GRB000418: HST/STIS Second-epoch Observations
  27. X-ray precursors to the large flare from SGR 1900+14
  28. GRB010214, optical observations
  29. GRB010427, Gamma Ray Observations
  30. SGR 1900+14: No evidence of extended X-ray emission
  31. SGR 1900+14 : RXTE observations
  32. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  33. SGR1900+14 - correction
  34. SGR1900+14
  35. SGR 1900+14: Correction to GCN 1049
  36. GRB 010222 /corrections to VBT data
  37. Millimeter observation of SGR 1900+14
  38. SGR 1900+14: Detection of extended X-ray emission
  39. Chandra Observations of SGR 1900+14
  40. SGR 1900+14, Chandra observations
  41. Chandra Observations of SGR 1900+14
  42. Possible precursor to the SGR1900+14 giant burst
  43. SGR1900+14, I-band observations
  44. IPN Triangulation of the Giant Flare from SGR1900+14
  45. GRB010412, field photometry
  46. Giant flare from SGR1900+14
  47. GRB 010326b Optical Observations
  48. GRB010412: Optical observations
  49. GRB010412: Optical observations
  50. GRB010412: BeppoSAX GRBM and WFC observations
  51. IPN Triangulation of GRB010412
  52. GRB010412: refined positions from BeppoSAX
  53. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  54. BeppoSAX GRB ALERT: GRB010412
  55. GRB Observation Report
  56. GRB010324, revised field photometry
  57. REVISED LOCATION OF GRB010326A
  58. GRB 980326: Late-time HST/STIS observations
  59. GRB010324, field photometry
  60. GRB010326B, field photometry
  61. GRB010326, field photometry
  62. GRB010220, field photometry
  63. Further Optical Observations of GRB 010324
  64. GRB010222, CXO X-ray observations
  65. GRB 010326A: Further optical observations
  66. GRB010324: BeppoSAX/GRBM data
  67. GRB 010326B: Optical observations
  68. GRB010324, optical observations
  69. GRB010326B: Localization by HETE (2nd GRB for this date)
  70. GRB 010326: Optical observations
  71. GRB 010326 optical observations
  72. GRB010326: Refined Localization by HETE
  73. GRB010326: Localization by HETE
  74. Duration, ECT, peak flux and fluence of GRB010324
  75. Optical Observations of GRB 010324
  76. IPN TRIANGULATION OF GRB010324
  77. GRB990705, VLT-FORS1 observations of the host galaxy
  78. GRB010222, late-time optical observation
  79. Support extension to the BeppoSAX mission
  80. GRB 010222 - HEGRA GeV/TeV Observations
  81. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  82. GRB010222: Chandra X-ray Observatory Observation
  83. GRB010222: Sub-millimeter vanishing act
  84. GRB010222 - Optical observation
  85. GRB 010222, Optical Observations
  86. GRB010220 optical obsercations
  87. GRB010222 - Optical observation
  88. GRB 010222: High-Resolution Keck Spectroscopy
  89. GRB010222: Optical observation and decay
  90. GRB 010214, I-band data
  91. Sub-millimeter Excess/GRB 010222
  92. GRB 010222
  93. GRB 010222 HST/Chandra TOO
  94. GRB 010222
  95. GRB010222 further R-band photometry
  96. GRB010222: R-band data
  97. GRB010222 Optical observations
  98. GRB 010222: Keck Spectroscopy
  99. GRB010214, field photometry
  100. GRB010222, field photometry

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