Skip to main content
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"

37513 results found.

  1. GRB011130 (=XRF011130): Revised Localization of an X-ray
  2. GRB001109, Radio Monitoring
  3. GRB 011121: Errata URL
  4. GRB 011121
  5. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  6. GRB 011121: J-band observations
  7. GRB 011121: NIR observations, host galaxy?
  8. GRB 011121: HST Scheduled
  9. GRB011121: fainter still
  10. Correction: GCN1157 (GRB 011121)
  11. GRB 011121: Radio Observations
  12. GRB 011121 J-Band Astrometry
  13. GRB011121: continued decay
  14. GRB 011121: Detection of Bright IR Counterpart
  15. GRB011121: possible redshift, continued decay
  16. IPN triangulation of GRB011121
  17. BEPPOSAX GRB011121
  18. GRB 011030: TNG K-band observation
  19. XRF011030: Chandra Observations
  20. GRB 011030: K-band observations
  21. GRB 011030 R band observations
  22. GRB 011030 I-band Observation
  23. The X-ray Flash 011030 ('GRB 011030')
  24. Non-triggered burst 011030 ("GRB 011030")
  25. The Radio Afterglow from the X-ray Rich GRB 011030
  26. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  27. GRB 970828: HST Observations of the Host Galaxy
  28. GRB 000131: HST Detection of the Host Galaxy
  29. GRB 970828: HST Observations of the Host Galaxy
  30. GRB010921, optical observation
  31. GRB 011019 optical observation
  32. GRB011019: Subaru Optical Observations
  33. GRB 011030 I-band Observations
  34. GRB 011030 K-band Observations
  35. GRB010921, optical observations
  36. GRB 011030, WSRT radio observations
  37. GRB011030 - further refinement WFC position
  38. GRB 011030, Radio observations
  39. GRB 011030, R-band observations
  40. BeppoSAX ALERT: Possible X-ray rich GRB011030
  41. GRB 010921: Possible supernova component
  42. GRB011019: NEAT Optical Observations
  43. GRB010921, optical observation at early time
  44. GRB 010921, I-band observations
  45. GRB011019: Optical observations
  46. GRB011019, optical observations
  47. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  48. GRB010921: Spectroscopy of the Host Galaxy
  49. GRB 010921: The afterglow of HETE #1761
  50. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  51. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  52. GRB010923 as seen by BeppoSAX GRBM
  53. GRB010928(=H1770): Localization of a Long GRB by HETE
  54. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  55. GRB010921, negative optical observations
  56. GRB010921 field photometry
  57. GRB010921 Optical Observations
  58. GRB 010921 DPOSS Images Available
  59. IPN triangulation of GRB010921 (=H1761)
  60. H1761: A Bright GRB Detected by HETE
  61. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  62. HETE Trigger #1760 (GRB 010920B?): a new optical source
  63. HETE Trigger #1759 (GRB 010920?) optical observations
  64. GRB001109, Host Galaxy Astrometry
  65. GRB000926, Host Galaxy Observations
  66. GRB001109, Host Galaxy Spectroscopic Observations
  67. Probable SGR or Short Duration GRB Detected by HETE
  68. GRB000926 Host Galaxy Observations
  69. GRB 010222: HST observations -- host galaxy and late-time decay
  70. BeppoSAX/GRBM detection of GRB 010801
  71. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  72. GRB 010222 - WHT BVRI images
  73. GRB 010629 Optical Observations
  74. GRB010629: Optical Observations
  75. GRB010629, optical observations
  76. IPN triangulation of GRB010629
  77. GRB010629: A Burst Localized by HETE
  78. Possible burst from SGR1806-20
  79. IPN detection of SGR1900+14
  80. GRB 00630: Host Galaxy
  81. IPN triangulation of GRB010613
  82. IPN triangulation of GRB010612
  83. HETE Fully-Automated GCN Notices
  84. GRB000301C: Late-time HST/STIS observation
  85. GRB010518: a faint BeppoSAX detection
  86. GRB000418: HST/STIS Second-epoch Observations
  87. GRB010427, Gamma Ray Observations
  88. SGR1900+14
  89. GRB 010222 /corrections to VBT data
  90. Possible precursor to the SGR1900+14 giant burst
  91. IPN Triangulation of the Giant Flare from SGR1900+14
  92. GRB010412, field photometry
  93. GRB 010326b Optical Observations
  94. GRB010412: Optical observations
  95. GRB010412: Optical observations
  96. IPN Triangulation of GRB010412
  97. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  98. BeppoSAX GRB ALERT: GRB010412
  99. GRB Observation Report
  100. GRB010324, revised field photometry

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