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"

21770 results found.

  1. GRB 011211: Evidence for an Optical Break
  2. GRB 011212: optical observation at Oslo (relayed)
  3. GRB 011211, Optical Observations
  4. GRB011212, BVRI field photometry
  5. GRB011211, BVRI field photometry
  6. Fading of the optical source associated of XRF 011211
  7. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  8. BeppoSAX Alert: GRB011211(=XRF011211)
  9. GRB011130 (XRF011130) Chandra Observations
  10. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  11. GRB 011130, K band observations
  12. GRB011130 (XRF011130) SDSS PT i-band observations
  13. XRF011130: Infrared Observations
  14. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  15. GRB 011121: J-band observations
  16. GRB 011121: NIR observations, host galaxy?
  17. GRB010921 - Milagro GeV/TeV Observations
  18. GRB011121: UBRI Observations
  19. GRB 011121: Radio Observations
  20. GRB 011121 J-Band Astrometry
  21. GRB 011121: Detection of Bright IR Counterpart
  22. GRB011121: possible redshift, continued decay
  23. IPN triangulation of GRB011121
  24. BEPPOSAX GRB011121
  25. GRB 011030: TNG K-band observation
  26. XRF011030: J and K band observations
  27. XRF011030: Chandra Observations
  28. GRB011030: Z-band observations
  29. GRB 011030 R band observations
  30. Non-triggered burst 011030 ("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. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  36. GRB011019: Subaru Optical Observations
  37. GRB011030 - further refinement WFC position
  38. GRB011030: radio search
  39. GRB 011030, R-band observations
  40. BeppoSAX ALERT: Possible X-ray rich GRB011030
  41. GRB 010921: Possible supernova component
  42. GRB010921, optical observation at early time
  43. GRB 010921, I-band observations
  44. GRB011019, optical observations
  45. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  46. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  47. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  48. GRB010928(=H1770): Localization of a Long GRB by HETE
  49. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  50. GRB010921, negative optical observations
  51. GRB010921 field photometry
  52. H1761: A Bright GRB Detected by HETE
  53. GRB000926, Host Galaxy Observations
  54. GRB001109, Host Galaxy Spectroscopic Observations
  55. GRB 010222: HST observations -- host galaxy and late-time decay
  56. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  57. GRB 010222 - WHT BVRI images
  58. GRB 010629 Optical Observations
  59. SGR1900+14: High Fluence Burst Localized by HETE
  60. GRB010629, optical observations
  61. IPN triangulation of GRB010629
  62. GRB010629: A Burst Localized by HETE
  63. SGR1900+14: Second Burst Localized by HETE
  64. SGR1900+14: A Burst Localized by HETE
  65. SGR1806-20: A Second, Intense Burst Localized by HETE
  66. SGR1806-20: Localization by HETE
  67. HETE Fully-Automated GCN Notices
  68. GRB000301C: Late-time HST/STIS observation
  69. GRB010518: a faint BeppoSAX detection
  70. GRB000418: HST/STIS Second-epoch Observations
  71. X-ray precursors to the large flare from SGR 1900+14
  72. GRB010427, Gamma Ray Observations
  73. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  74. SGR 1900+14: Correction to GCN 1049
  75. Millimeter observation of SGR 1900+14
  76. SGR 1900+14: Detection of extended X-ray emission
  77. SGR 1900+14, Chandra observations
  78. Possible precursor to the SGR1900+14 giant burst
  79. SGR1900+14, I-band observations
  80. IPN Triangulation of the Giant Flare from SGR1900+14
  81. GRB010412, field photometry
  82. Giant flare from SGR1900+14
  83. GRB 010326b Optical Observations
  84. GRB010412: BeppoSAX GRBM and WFC observations
  85. GRB010324, revised field photometry
  86. REVISED LOCATION OF GRB010326A
  87. GRB 980326: Late-time HST/STIS observations
  88. GRB010324, field photometry
  89. GRB010326B, field photometry
  90. GRB010326, field photometry
  91. GRB010220, field photometry
  92. Further Optical Observations of GRB 010324
  93. GRB010222, CXO X-ray observations
  94. GRB010324, optical observations
  95. GRB010326B: Localization by HETE (2nd GRB for this date)
  96. GRB 010326 optical observations
  97. GRB010326: Refined Localization by HETE
  98. GRB010326: Localization by HETE
  99. Optical Observations of GRB 010324
  100. GRB010222, late-time optical observation

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