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"

36355 results found.

  1. GRB 011130 I-band Observation
  2. GRB011130 (XRF011130) optical observations
  3. GRB011130 (XRF011130) SDSS PT i-band observations
  4. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  5. XRF011130: NEAT Optical Observations
  6. GRB011130 (=XRF011130): Revised Localization of an X-ray
  7. GRB001109, Radio Monitoring
  8. GRB 011121: Errata URL
  9. GRB 011121
  10. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  11. GRB 011121: J-band observations
  12. GRB 011121: NIR observations, host galaxy?
  13. GRB 011121: HST Scheduled
  14. GRB011121: fainter still
  15. Correction: GCN1157 (GRB 011121)
  16. GRB 011121: Radio Observations
  17. GRB 011121 J-Band Astrometry
  18. GRB011121: continued decay
  19. GRB 011121: Detection of Bright IR Counterpart
  20. GRB011121: possible redshift, continued decay
  21. IPN triangulation of GRB011121
  22. BEPPOSAX GRB011121
  23. GRB 011030: TNG K-band observation
  24. XRF011030: Chandra Observations
  25. GRB 011030: K-band observations
  26. GRB 011030 R band observations
  27. GRB 011030 I-band Observation
  28. The X-ray Flash 011030 ('GRB 011030')
  29. Non-triggered burst 011030 ("GRB 011030")
  30. The Radio Afterglow from the X-ray Rich GRB 011030
  31. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  32. GRB 970828: HST Observations of the Host Galaxy
  33. GRB 000131: HST Detection of the Host Galaxy
  34. GRB 970828: HST Observations of the Host Galaxy
  35. GRB010921, optical observation
  36. GRB 011019 optical observation
  37. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  38. GRB011019: Subaru Optical Observations
  39. GRB 011030 I-band Observations
  40. GRB 011030 K-band Observations
  41. GRB010921, optical observations
  42. GRB 011030, WSRT radio observations
  43. GRB011030 - further refinement WFC position
  44. GRB 011030, Radio observations
  45. GRB 011030, R-band observations
  46. BeppoSAX ALERT: Possible X-ray rich GRB011030
  47. GRB 010921: Possible supernova component
  48. GRB011019: NEAT Optical Observations
  49. GRB010921, optical observation at early time
  50. GRB 010921, I-band observations
  51. GRB011019: Optical observations
  52. GRB011019, optical observations
  53. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  54. GRB010921: Spectroscopy of the Host Galaxy
  55. GRB 010921: The afterglow of HETE #1761
  56. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  57. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  58. GRB010923 as seen by BeppoSAX GRBM
  59. GRB010928(=H1770): Localization of a Long GRB by HETE
  60. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  61. GRB010921, negative optical observations
  62. GRB010921 field photometry
  63. GRB010921 Optical Observations
  64. GRB 010921 DPOSS Images Available
  65. IPN triangulation of GRB010921 (=H1761)
  66. H1761: A Bright GRB Detected by HETE
  67. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  68. HETE Trigger #1760 (GRB 010920B?): a new optical source
  69. HETE Trigger #1759 (GRB 010920?) optical observations
  70. GRB001109, Host Galaxy Astrometry
  71. GRB000926, Host Galaxy Observations
  72. GRB001109, Host Galaxy Spectroscopic Observations
  73. Probable SGR or Short Duration GRB Detected by HETE
  74. GRB000926 Host Galaxy Observations
  75. GRB 010222: HST observations -- host galaxy and late-time decay
  76. BeppoSAX/GRBM detection of GRB 010801
  77. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  78. GRB 010222 - WHT BVRI images
  79. GRB 010629 Optical Observations
  80. GRB010629: Optical Observations
  81. SGR1900+14: High Fluence Burst Localized by HETE
  82. GRB010629, optical observations
  83. IPN triangulation of GRB010629
  84. GRB010629: A Burst Localized by HETE
  85. SGR1900+14: A Burst Localized by HETE
  86. Possible burst from SGR1806-20
  87. IPN detection of SGR1900+14
  88. SGR1806-20: A Second, Intense Burst Localized by HETE
  89. GRB 00630: Host Galaxy
  90. IPN triangulation of GRB010613
  91. IPN triangulation of GRB010612
  92. HETE Fully-Automated GCN Notices
  93. GRB000301C: Late-time HST/STIS observation
  94. GRB010518: a faint BeppoSAX detection
  95. GRB000418: HST/STIS Second-epoch Observations
  96. GRB010427, Gamma Ray Observations
  97. SGR 1900+14 : RXTE observations
  98. SGR1900+14
  99. GRB 010222 /corrections to VBT data
  100. SGR 1900+14, Chandra 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