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"

28045 results found.

  1. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  2. GRB020124: Optical observations
  3. GRB 020124: Optical observations
  4. GRB 020124: Optical afterglow
  5. GRB020124(=H1896): Localization of a Long GRB by HETE
  6. Possible optical counterpart to a GRB
  7. GRB011212, Optical Observations
  8. Optical polarization observations for GRB011211
  9. GRB 011211: Detection of the Probable Host Galaxy
  10. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  11. GRB 011130: Optical Observations of X-ray and Radio Sources
  12. GRB 011212: optical observation at Asiago
  13. GRB 011211: Evidence for an Optical Break
  14. GRB 011211: TNG Spectroscopic Observations
  15. optical follow-up of GRB(XRF) 011211
  16. GRB 011212: optical observation at Oslo (relayed)
  17. GRB 011211, Optical Observations
  18. GRB011212, BVRI field photometry
  19. GRB011211, BVRI field photometry
  20. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  21. Fading of the optical source associated of XRF 011211
  22. GRB 011211 Optical Observations: Likely Afterglow
  23. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  24. GRB011130 (XRF011130) Chandra Observations
  25. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  26. GRB 011130, K band observations
  27. GRB011130, optical observations
  28. GRB011130 (=XRF011130): Second Revised Localization by HETE
  29. GRB011130 (XRF011130) SDSS PT i-band observations
  30. XRF011130: Infrared Observations
  31. GRB 011121
  32. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  33. GRB 011121: J-band observations
  34. GRB 011121: NIR observations, host galaxy?
  35. GRB011121: UBRI Observations
  36. GRB 011121 J-Band Astrometry
  37. GRB 011121: Detection of Bright IR Counterpart
  38. GRB011121: possible redshift, continued decay
  39. GRB 011030: TNG K-band observation
  40. XRF011030: J and K band observations
  41. XRF011030: Chandra Observations
  42. GRB011030: Z-band observations
  43. GRB 011030 R band observations
  44. GRB 011030 I-band Observation
  45. The X-ray Flash 011030 ('GRB 011030')
  46. Non-triggered burst 011030 ("GRB 011030")
  47. The Radio Afterglow from the X-ray Rich GRB 011030
  48. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  49. GRB 970828: HST Observations of the Host Galaxy
  50. GRB 000131: HST Detection of the Host Galaxy
  51. GRB 970828: HST Observations of the Host Galaxy
  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. GRB011030 - further refinement WFC position
  58. GRB 011030, Radio observations
  59. GRB011030: radio search
  60. GRB 010921: Possible supernova component
  61. GRB010921, optical observation at early time
  62. GRB 010921, I-band observations
  63. GRB011019, optical observations
  64. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  65. GRB 010921: The afterglow of HETE #1761
  66. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  67. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  68. GRB010923 as seen by BeppoSAX GRBM
  69. GRB010928(=H1770): Localization of a Long GRB by HETE
  70. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  71. GRB010921, negative optical observations
  72. GRB010921 field photometry
  73. H1761: A Bright GRB Detected by HETE
  74. GRB000926, Host Galaxy Observations
  75. GRB001109, Host Galaxy Spectroscopic Observations
  76. Probable SGR or Short Duration GRB Detected by HETE
  77. GCN and HETE status
  78. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  79. GRB 010222 - WHT BVRI images
  80. SGR1900+14 burst seen by HETE: BeppoSAX data
  81. GRB 010629 Optical Observations
  82. SGR1900+14: High Fluence Burst Localized by HETE
  83. GRB010629, optical observations
  84. GRB010629: A Burst Localized by HETE
  85. SGR1900+14: Second Burst Localized by HETE
  86. SGR1900+14: A Burst Localized by HETE
  87. SGR1806-20: A Second, Intense Burst Localized by HETE
  88. SGR1806-20: Localization by HETE
  89. HETE Fully-Automated GCN Notices
  90. GRB000301C: Late-time HST/STIS observation
  91. GRB010518: a faint BeppoSAX detection
  92. GRB000418: HST/STIS Second-epoch Observations
  93. X-ray precursors to the large flare from SGR 1900+14
  94. GRB010427, Gamma Ray Observations
  95. SGR 1900+14: No evidence of extended X-ray emission
  96. SGR 1900+14 : RXTE observations
  97. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  98. SGR 1900+14: Correction to GCN 1049
  99. GRB 010222 /corrections to VBT data
  100. Millimeter observation of SGR 1900+14

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