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"

37524 results found.

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

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