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"

37104 results found.

  1. GRB011019, optical observations
  2. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  3. GRB010921: Spectroscopy of the Host Galaxy
  4. GRB 010921: The afterglow of HETE #1761
  5. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  6. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  7. GRB010923 as seen by BeppoSAX GRBM
  8. GRB010928(=H1770): Localization of a Long GRB by HETE
  9. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  10. GRB010921, negative optical observations
  11. GRB010921 field photometry
  12. GRB010921 Optical Observations
  13. GRB 010921 DPOSS Images Available
  14. IPN triangulation of GRB010921 (=H1761)
  15. H1761: A Bright GRB Detected by HETE
  16. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  17. HETE Trigger #1760 (GRB 010920B?): a new optical source
  18. HETE Trigger #1759 (GRB 010920?) optical observations
  19. GRB001109, Host Galaxy Astrometry
  20. GRB000926, Host Galaxy Observations
  21. GRB001109, Host Galaxy Spectroscopic Observations
  22. Probable SGR or Short Duration GRB Detected by HETE
  23. GRB000926 Host Galaxy Observations
  24. GRB 010222: HST observations -- host galaxy and late-time decay
  25. BeppoSAX/GRBM detection of GRB 010801
  26. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  27. GRB 010222 - WHT BVRI images
  28. GRB 010629 Optical Observations
  29. GRB010629: Optical Observations
  30. SGR1900+14: High Fluence Burst Localized by HETE
  31. GRB010629, optical observations
  32. IPN triangulation of GRB010629
  33. GRB010629: A Burst Localized by HETE
  34. SGR1900+14: A Burst Localized by HETE
  35. Possible burst from SGR1806-20
  36. IPN detection of SGR1900+14
  37. SGR1806-20: A Second, Intense Burst Localized by HETE
  38. GRB 00630: Host Galaxy
  39. IPN triangulation of GRB010613
  40. IPN triangulation of GRB010612
  41. HETE Fully-Automated GCN Notices
  42. GRB000301C: Late-time HST/STIS observation
  43. GRB010518: a faint BeppoSAX detection
  44. GRB000418: HST/STIS Second-epoch Observations
  45. GRB010427, Gamma Ray Observations
  46. SGR 1900+14 : RXTE observations
  47. SGR1900+14
  48. GRB 010222 /corrections to VBT data
  49. SGR 1900+14, Chandra observations
  50. Possible precursor to the SGR1900+14 giant burst
  51. IPN Triangulation of the Giant Flare from SGR1900+14
  52. GRB010412, field photometry
  53. GRB 010326b Optical Observations
  54. GRB010412: Optical observations
  55. GRB010412: Optical observations
  56. IPN Triangulation of GRB010412
  57. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  58. BeppoSAX GRB ALERT: GRB010412
  59. GRB Observation Report
  60. GRB010324, revised field photometry
  61. REVISED LOCATION OF GRB010326A
  62. GRB 980326: Late-time HST/STIS observations
  63. GRB010324, field photometry
  64. GRB010326B, field photometry
  65. GRB010326, field photometry
  66. GRB010220, field photometry
  67. Further Optical Observations of GRB 010324
  68. GRB 010326A: Further optical observations
  69. GRB010324: BeppoSAX/GRBM data
  70. GRB 010326B: Optical observations
  71. GRB010324, optical observations
  72. GRB010326B: Localization by HETE (2nd GRB for this date)
  73. GRB 010326: Optical observations
  74. GRB 010326 optical observations
  75. GRB010326: Refined Localization by HETE
  76. GRB010326: Localization by HETE
  77. Duration, ECT, peak flux and fluence of GRB010324
  78. Optical Observations of GRB 010324
  79. IPN TRIANGULATION OF GRB010324
  80. GRB990705, VLT-FORS1 observations of the host galaxy
  81. GRB010222, late-time optical observation
  82. Support extension to the BeppoSAX mission
  83. GRB 010222 - HEGRA GeV/TeV Observations
  84. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  85. GRB010222: Chandra X-ray Observatory Observation
  86. GRB010222: Sub-millimeter vanishing act
  87. GRB 010222, Optical Observations
  88. GRB 010222: High-Resolution Keck Spectroscopy
  89. GRB 010214, I-band data
  90. Sub-millimeter Excess/GRB 010222
  91. GRB 010222
  92. GRB 010222 HST/Chandra TOO
  93. GRB 010222
  94. GRB010222 further R-band photometry
  95. GRB010222: R-band data
  96. GRB010222 Optical observations
  97. GRB 010222: Keck Spectroscopy
  98. GRB010214, field photometry
  99. GRB010222, field photometry
  100. GRB010222 further R-band photometry

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