Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
Updates to LVK & CHIME Notices, Schema v7.2.3! 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. HETE Trigger #1760 (GRB 010920B?): a new optical source
  2. HETE Trigger #1759 (GRB 010920?) optical observations
  3. GRB001109, Host Galaxy Astrometry
  4. GRB000926, Host Galaxy Observations
  5. GRB001109, Host Galaxy Spectroscopic Observations
  6. Probable SGR or Short Duration GRB Detected by HETE
  7. GRB000926 Host Galaxy Observations
  8. GRB 010222: HST observations -- host galaxy and late-time decay
  9. BeppoSAX/GRBM detection of GRB 010801
  10. GCN and HETE status
  11. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  12. BeppoSAX/GRBM detection of GRB010728
  13. GRB 010222 - WHT BVRI images
  14. SGR1900+14 burst seen by HETE: BeppoSAX data
  15. GRB 010629 Optical Observations
  16. GRB010629: Optical Observations
  17. SGR1900+14: High Fluence Burst Localized by HETE
  18. GRB010629, optical observations
  19. IPN triangulation of GRB010629
  20. GRB010629: A Burst Localized by HETE
  21. SGR1900+14: Second Burst Localized by HETE
  22. SGR1900+14: A Burst Localized by HETE
  23. Possible burst from SGR1806-20
  24. IPN detection of SGR1900+14
  25. SGR1806-20: A Second, Intense Burst Localized by HETE
  26. GRB 00630: Host Galaxy
  27. SGR1806-20: Localization by HETE
  28. IPN triangulation of GRB010613
  29. IPN triangulation of GRB010612
  30. IPN triangulation of GRB010612
  31. HETE Fully-Automated GCN Notices
  32. GRB000301C: Late-time HST/STIS observation
  33. GRB010518: a faint BeppoSAX detection
  34. GRB000418: HST/STIS Second-epoch Observations
  35. X-ray precursors to the large flare from SGR 1900+14
  36. GRB010214, optical observations
  37. GRB010427, Gamma Ray Observations
  38. SGR 1900+14: No evidence of extended X-ray emission
  39. SGR 1900+14 : RXTE observations
  40. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  41. SGR1900+14 - correction
  42. SGR1900+14
  43. SGR 1900+14: Correction to GCN 1049
  44. GRB 010222 /corrections to VBT data
  45. Millimeter observation of SGR 1900+14
  46. SGR 1900+14: Detection of extended X-ray emission
  47. Chandra Observations of SGR 1900+14
  48. SGR 1900+14, Chandra observations
  49. Chandra Observations of SGR 1900+14
  50. Possible precursor to the SGR1900+14 giant burst
  51. SGR1900+14, I-band observations
  52. IPN Triangulation of the Giant Flare from SGR1900+14
  53. GRB010412, field photometry
  54. Giant flare from SGR1900+14
  55. GRB 010326b Optical Observations
  56. GRB010412: Optical observations
  57. GRB010412: Optical observations
  58. GRB010412: BeppoSAX GRBM and WFC observations
  59. IPN Triangulation of GRB010412
  60. GRB010412: refined positions from BeppoSAX
  61. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  62. BeppoSAX GRB ALERT: GRB010412
  63. GRB Observation Report
  64. GRB010324, revised field photometry
  65. REVISED LOCATION OF GRB010326A
  66. GRB 980326: Late-time HST/STIS observations
  67. GRB010324, field photometry
  68. GRB010326B, field photometry
  69. GRB010326, field photometry
  70. GRB010220, field photometry
  71. Further Optical Observations of GRB 010324
  72. GRB010222, CXO X-ray observations
  73. GRB 010326A: Further optical observations
  74. GRB010324: BeppoSAX/GRBM data
  75. GRB 010326B: Optical observations
  76. GRB010324, optical observations
  77. GRB010326B: Localization by HETE (2nd GRB for this date)
  78. GRB 010326: Optical observations
  79. GRB 010326 optical observations
  80. GRB010326: Refined Localization by HETE
  81. GRB010326: Localization by HETE
  82. Duration, ECT, peak flux and fluence of GRB010324
  83. Optical Observations of GRB 010324
  84. IPN TRIANGULATION OF GRB010324
  85. GRB990705, VLT-FORS1 observations of the host galaxy
  86. GRB010222, late-time optical observation
  87. Support extension to the BeppoSAX mission
  88. GRB 010222 - HEGRA GeV/TeV Observations
  89. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  90. GRB010222: Chandra X-ray Observatory Observation
  91. GRB010222: Sub-millimeter vanishing act
  92. GRB010222 - Optical observation
  93. GRB 010222, Optical Observations
  94. GRB010220 optical obsercations
  95. GRB010222 - Optical observation
  96. GRB 010222: High-Resolution Keck Spectroscopy
  97. GRB010222: Optical observation and decay
  98. GRB 010214, I-band data
  99. Sub-millimeter Excess/GRB 010222
  100. GRB 010222

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