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"

32507 results found.

  1. GRB 011030, Radio observations
  2. GRB011030: radio search
  3. GRB 011030, R-band observations
  4. BeppoSAX ALERT: Possible X-ray rich GRB011030
  5. GRB 010921: Possible supernova component
  6. GRB011019: ROTSE-III optical observations
  7. GRB 010921, I-band observations
  8. GRB011019: Optical observations
  9. GRB011019, optical observations -- correction
  10. GRB011019, optical observations
  11. GRB010921: Spectroscopy of the Host Galaxy
  12. GRB 010921: The afterglow of HETE #1761
  13. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  14. GRB010923 as seen by BeppoSAX GRBM
  15. GRB010928(=H1770): Localization of a Long GRB by HETE
  16. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  17. GRB010921, negative optical observations
  18. GRB010921 field photometry
  19. GRB 010921 DPOSS Images Available
  20. IPN triangulation of GRB010921 (=H1761)
  21. H1761: A Bright GRB Detected by HETE
  22. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  23. GRB001109, Host Galaxy Astrometry
  24. GRB000926, Host Galaxy Observations
  25. GRB001109, Host Galaxy Spectroscopic Observations
  26. Probable SGR or Short Duration GRB Detected by HETE
  27. GCN and HETE status
  28. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  29. GRB 010222 - WHT BVRI images
  30. SGR1900+14 burst seen by HETE: BeppoSAX data
  31. GRB 010629 Optical Observations
  32. GRB010629: Optical Observations
  33. SGR1900+14: High Fluence Burst Localized by HETE
  34. GRB010629, optical observations
  35. IPN triangulation of GRB010629
  36. SGR1900+14: Second Burst Localized by HETE
  37. SGR1900+14: A Burst Localized by HETE
  38. Possible burst from SGR1806-20
  39. SGR1806-20: A Second, Intense Burst Localized by HETE
  40. IPN triangulation of GRB010613
  41. IPN triangulation of GRB010612
  42. IPN triangulation of GRB010612
  43. HETE Fully-Automated GCN Notices
  44. GRB000301C: Late-time HST/STIS observation
  45. GRB000418: HST/STIS Second-epoch Observations
  46. X-ray precursors to the large flare from SGR 1900+14
  47. GRB010214, optical observations
  48. SGR 1900+14: No evidence of extended X-ray emission
  49. SGR 1900+14 : RXTE observations
  50. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  51. SGR1900+14 - correction
  52. SGR1900+14
  53. SGR 1900+14: Correction to GCN 1049
  54. Millimeter observation of SGR 1900+14
  55. SGR 1900+14: Detection of extended X-ray emission
  56. Chandra Observations of SGR 1900+14
  57. SGR 1900+14, Chandra observations
  58. Chandra Observations of SGR 1900+14
  59. Possible precursor to the SGR1900+14 giant burst
  60. SGR1900+14, I-band observations
  61. IPN Triangulation of the Giant Flare from SGR1900+14
  62. GRB 010326b Optical Observations
  63. GRB010412: Optical observations
  64. GRB010412: Optical observations
  65. IPN Triangulation of GRB010412
  66. GRB Observation Report
  67. REVISED LOCATION OF GRB010326A
  68. GRB 980326: Late-time HST/STIS observations
  69. GRB010324, field photometry
  70. GRB010326B, field photometry
  71. GRB010326, field photometry
  72. GRB010220, field photometry
  73. Further Optical Observations of GRB 010324
  74. GRB010222, CXO X-ray observations
  75. GRB010324: BeppoSAX/GRBM data
  76. GRB010324, optical observations
  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. GRB 010222 - HEGRA GeV/TeV Observations
  83. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  84. GRB010222: Chandra X-ray Observatory Observation
  85. GRB010222: Sub-millimeter vanishing act
  86. GRB010222 - Optical observation
  87. GRB 010222, Optical Observations
  88. GRB010220 optical obsercations
  89. GRB010222 - Optical observation
  90. GRB 010222: High-Resolution Keck Spectroscopy
  91. GRB010222: Optical observation and decay
  92. GRB 010214, I-band data
  93. Sub-millimeter Excess/GRB 010222
  94. GRB 010222
  95. GRB 010222 HST/Chandra TOO
  96. GRB010222 further R-band photometry
  97. GRB010222: R-band data
  98. GRB010222 Optical observations
  99. GRB 010222: Keck Spectroscopy
  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