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"

41706 results found.

  1. GRB 011130: Magellan spectroscopy
  2. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  3. GRB011130, optical observations
  4. GRB 011130, K band observations
  5. GRB011130, optical observations
  6. GRB011130 (=XRF011130): Second Revised Localization by HETE
  7. GRB011130 (XRF011130) optical observations
  8. GRB011130 (XRF011130) SDSS PT i-band observations
  9. XRF011130: Infrared Observations
  10. GRB011130, Radio Observations
  11. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  12. GRB011130 (=XRF011130), Optical Observations
  13. XRF011130: NEAT Optical Observations
  14. GRB011130 (=XRF011130): Revised Localization of an X-ray
  15. GRB001109, Radio Monitoring
  16. GRB 011121
  17. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  18. GRB 011121: J-band observations
  19. GRB 011121: NIR observations, host galaxy?
  20. GRB010921 - Milagro GeV/TeV Observations
  21. GRB 011121: HST Scheduled
  22. GRB011121: fainter still
  23. Correction: GCN1157 (GRB 011121)
  24. GRB011121: UBRI Observations
  25. GRB011121
  26. GRB 011121: Radio Observations
  27. GRB 011121 J-Band Astrometry
  28. GRB011121: continued decay
  29. GRB 011121: Detection of Bright IR Counterpart
  30. GRB011121: possible redshift, continued decay
  31. GRB011121: fading behavior
  32. GRB011121: possible optical counterpart
  33. IPN triangulation of GRB011121
  34. BEPPOSAX GRB011121
  35. GRB 011030: TNG K-band observation
  36. XRF011030: J and K band observations
  37. GRB011030, optical observation
  38. XRF011030: Chandra Observations
  39. GRB 011030: K-band observations
  40. GRB011030: Z-band observations
  41. GRB 011030 R band observations
  42. GRB 011030 I-band Observation
  43. The X-ray Flash 011030 ('GRB 011030')
  44. Non-triggered burst 011030 ("GRB 011030")
  45. The Radio Afterglow from the X-ray Rich GRB 011030
  46. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  47. GRB 970828: HST Observations of the Host Galaxy
  48. GRB 000131: HST Detection of the Host Galaxy
  49. GRB 970828: HST Observations of the Host Galaxy
  50. GRB010921, optical observation
  51. GRB 011019 optical observation
  52. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  53. GRB011019: Subaru Optical Observations
  54. GRB 011030 I-band Observations
  55. GRB 011030 K-band Observations
  56. GRB010921, optical observations
  57. GRB 011030, WSRT radio observations
  58. GRB011030 - further refinement WFC position
  59. GRB 011030, Radio observations
  60. GRB 011030, R-band observations
  61. BeppoSAX ALERT: Possible X-ray rich GRB011030
  62. GRB 010921: Possible supernova component
  63. GRB011019: NEAT Optical Observations
  64. GRB011019: ROTSE-III optical observations
  65. GRB010921, optical observation at early time
  66. GRB011019: Optical observations
  67. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  68. GRB010921: Spectroscopy of the Host Galaxy
  69. GRB 010921: The afterglow of HETE #1761
  70. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  71. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  72. GRB010923 as seen by BeppoSAX GRBM
  73. GRB010928(=H1770): Localization of a Long GRB by HETE
  74. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  75. GRB010921, negative optical observations
  76. GRB010921 field photometry
  77. GRB010921 Optical Observations
  78. GRB 010921 DPOSS Images Available
  79. IPN triangulation of GRB010921 (=H1761)
  80. H1761: A Bright GRB Detected by HETE
  81. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  82. HETE Trigger #1760 (GRB 010920B?): a new optical source
  83. HETE Trigger #1759 (GRB 010920?) optical observations
  84. GRB001109, Host Galaxy Astrometry
  85. GRB000926, Host Galaxy Observations
  86. GRB001109, Host Galaxy Spectroscopic Observations
  87. Probable SGR or Short Duration GRB Detected by HETE
  88. GRB000926 Host Galaxy Observations
  89. GRB 010222: HST observations -- host galaxy and late-time decay
  90. BeppoSAX/GRBM detection of GRB 010801
  91. GCN and HETE status
  92. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  93. BeppoSAX/GRBM detection of GRB010728
  94. GRB 010222 - WHT BVRI images
  95. SGR1900+14 burst seen by HETE: BeppoSAX data
  96. GRB010629: Optical Observations
  97. SGR1900+14: High Fluence Burst Localized by HETE
  98. GRB010629, optical observations
  99. IPN triangulation of GRB010629
  100. GRB010629: A Burst Localized by HETE

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