Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"
  1. GRB001109, Host Galaxy Spectroscopic Observations
  2. Probable SGR or Short Duration GRB Detected by HETE
  3. GRB000926 Host Galaxy Observations
  4. GRB 010222: HST observations -- host galaxy and late-time decay
  5. BeppoSAX/GRBM detection of GRB 010801
  6. GCN and HETE status
  7. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  8. BeppoSAX/GRBM detection of GRB010728
  9. GRB 010222 - WHT BVRI images
  10. SGR1900+14 burst seen by HETE: BeppoSAX data
  11. GRB 010629 Optical Observations
  12. GRB010629: Optical Observations
  13. SGR1900+14: High Fluence Burst Localized by HETE
  14. GRB010629, optical observations
  15. IPN triangulation of GRB010629
  16. GRB010629: A Burst Localized by HETE
  17. SGR1900+14: Second Burst Localized by HETE
  18. SGR1900+14: A Burst Localized by HETE
  19. Possible burst from SGR1806-20
  20. IPN detection of SGR1900+14
  21. SGR1806-20: A Second, Intense Burst Localized by HETE
  22. GRB 00630: Host Galaxy
  23. SGR1806-20: Localization by HETE
  24. IPN triangulation of GRB010613
  25. IPN triangulation of GRB010612
  26. IPN triangulation of GRB010612
  27. HETE Fully-Automated GCN Notices
  28. GRB000301C: Late-time HST/STIS observation
  29. GRB010518: a faint BeppoSAX detection
  30. GRB000418: HST/STIS Second-epoch Observations
  31. X-ray precursors to the large flare from SGR 1900+14
  32. GRB010214, optical observations
  33. GRB010427, Gamma Ray Observations
  34. SGR 1900+14: No evidence of extended X-ray emission
  35. SGR 1900+14 : RXTE observations
  36. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  37. SGR1900+14 - correction
  38. SGR1900+14
  39. SGR 1900+14: Correction to GCN 1049
  40. GRB 010222 /corrections to VBT data
  41. Millimeter observation of SGR 1900+14
  42. SGR 1900+14: Detection of extended X-ray emission
  43. Chandra Observations of SGR 1900+14
  44. SGR 1900+14, Chandra observations
  45. Chandra Observations of SGR 1900+14
  46. Possible precursor to the SGR1900+14 giant burst
  47. SGR1900+14, I-band observations
  48. IPN Triangulation of the Giant Flare from SGR1900+14
  49. GRB010412, field photometry
  50. Giant flare from SGR1900+14
  51. GRB 010326b Optical Observations
  52. GRB010412: Optical observations
  53. GRB010412: Optical observations
  54. GRB010412: BeppoSAX GRBM and WFC observations
  55. IPN Triangulation of GRB010412
  56. GRB010412: refined positions from BeppoSAX
  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. GRB010222, CXO X-ray observations
  69. GRB 010326A: Further optical observations
  70. GRB010324: BeppoSAX/GRBM data
  71. GRB 010326B: Optical observations
  72. GRB010324, optical observations
  73. GRB010326B: Localization by HETE (2nd GRB for this date)
  74. GRB 010326: Optical observations
  75. GRB 010326 optical observations
  76. GRB010326: Refined Localization by HETE
  77. GRB010326: Localization by HETE
  78. Duration, ECT, peak flux and fluence of GRB010324
  79. Optical Observations of GRB 010324
  80. IPN TRIANGULATION OF GRB010324
  81. GRB990705, VLT-FORS1 observations of the host galaxy
  82. GRB010222, late-time optical observation
  83. Support extension to the BeppoSAX mission
  84. GRB 010222 - HEGRA GeV/TeV Observations
  85. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  86. GRB010222: Chandra X-ray Observatory Observation
  87. GRB010222: Sub-millimeter vanishing act
  88. GRB010222 - Optical observation
  89. GRB 010222, Optical Observations
  90. GRB010220 optical obsercations
  91. GRB010222 - Optical observation
  92. GRB 010222: High-Resolution Keck Spectroscopy
  93. GRB010222: Optical observation and decay
  94. GRB 010214, I-band data
  95. Sub-millimeter Excess/GRB 010222
  96. GRB 010222
  97. GRB 010222 HST/Chandra TOO
  98. GRB 010222
  99. GRB010222 further R-band photometry
  100. GRB010222: R-band data

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov