Skip to main content
Due to the lapse in federal government funding, NASA is not updating this website. See the Operations FAQ for GCN impacts.
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

606 results found.

  1. DETECTION OF POLARIZATION OF THE RADIO EMISSION FROM SGR 1806-20
  2. VLA observations of SGR 1806-20
  3. SGR1806 VLA Observations
  4. VLA observations of SGR 1806-20
  5. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  6. Detection of the SGR 1806-20 giant outburst back-scattered by the
  7. The giant outburst from SGR 1806-20
  8. Giant flare from SGR 1806-20 detected by INTEGRAL
  9. Very high activity of SGR 1806-20
  10. Summary of the recent bursts from SGR 1806-20
  11. IBAS GRB Alert # 2034
  12. Bright bursts from SGR1806-20
  13. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  14. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  15. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  16. SGR 1806-20 still active
  17. An intense burst from SGR1806-20
  18. Very bright burst detected from SGR 1806-20
  19. Increase of SGR 1806-20 activity
  20. Bursting activity from SGR 1806-20 detected with IBAS
  21. Ongoing activity of SGR 1806-20
  22. GRB040706:observation at University of Miyazaki
  23. SGR 1806-20: no IR variability of the proposed counterparts
  24. SGR 1806-20, potential NIR counterpart
  25. Activivty of SGR 1806-20
  26. IBAS GRB Alerts n.1785 to 1791
  27. Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
  28. IBAS GRB Alert 1694
  29. IBAS GRB alerts 1679, 1680, 1681
  30. IBAS results on a burst from SGR1806-20
  31. IBAS alert 1180 refers to a burst from SGR 1806-20
  32. Ongoing Bursting Activity from SGR 1806-20 detected with IBAS
  33. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  34. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  35. A burst from SGR 1806-20 detected with IBAS
  36. IPN triangulation of GRB030926 (short/hard; large error box)
  37. IBAS detection of bursts from SGR 1806-20
  38. Radio Observations of SGR1806-20
  39. INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS
  40. Summary of recent IPN and HETE detections of SGR bursts
  41. Clarification of GCN 2354 on SGR1806-20
  42. IPN detection of continued activity from SGR1806-20
  43. 030813 SGR event (Konus-Wind observation)
  44. SGR 1808-20 (=H2802): A Possible new SGR
  45. SGR 1806-20, submm observations
  46. RXTE PCA Observations of SGR1806-20 Region
  47. HETE detection of burst from SGR1806-20
  48. GRB030329 observed as a sudden ionospheric disturbance (SID)
  49. IPN triangulation of GRB021219
  50. IPN detection of continued activity from SGR1806-20
  51. IPN detection of renewed activity from SGR1806-20
  52. IPN detection of continued SGR1900+14 activity
  53. IPN confirmation of the reactivation of SGR1900+14
  54. IPN detection of possible reactivation of SGR1900+14
  55. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  56. SGR1900+14 activity, November 2-4, 2002
  57. Detection of activity from SGR 1900+14 with the RXTE/PCA
  58. IPN detection of a burst from SGR1900+14
  59. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  60. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  61. AXP 1E2259+586: quasi-simultaneous optical observation
  62. AXP 1E2259+586 optical observations
  63. SGR-like Bursts from the AXP 1E 2259+586
  64. IPN detection of possible bursts from SGR1806-20
  65. XRF 020427: Sudden Ionospheric Disturbance (SID)
  66. Mars Odyssey joins the IPN
  67. IPN detection and localization of Cygnus X-1 flares
  68. RXTE Observations of SGR 1900+14
  69. SGR1900+14 activity
  70. IPN/HETE Detection of Bursts from SGR1900+14
  71. IPN detection of further activity from SGR1806-20
  72. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  73. Probable SGR or Short Duration GRB Detected by HETE
  74. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  75. Possible burst from SGR1806-20
  76. IPN detection of SGR1900+14
  77. X-ray precursors to the large flare from SGR 1900+14
  78. SGR 1900+14: No evidence of extended X-ray emission
  79. SGR 1900+14 : RXTE observations
  80. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  81. SGR1900+14
  82. SGR 1900+14: Correction to GCN 1049
  83. Millimeter observation of SGR 1900+14
  84. SGR 1900+14: Detection of extended X-ray emission
  85. Chandra Observations of SGR 1900+14
  86. SGR 1900+14, Chandra observations
  87. Chandra Observations of SGR 1900+14
  88. SGR1900+14, I-band observations
  89. SGR 1806-20 burst activity
  90. BATSE GRB trigger criteria
  91. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  92. GRB990308 not a new SGR
  93. GRB990308, Possible new SGR~0209+70
  94. SGR1900+14, BeppoSAX-GRBM observations
  95. SGR1627-41
  96. SGR1627-41, RXTE/ASM observations
  97. Reduced error box of SGR 1627-41
  98. SGR 1627-41
  99. Discovery of a new SGR source, SGR1627-41
  100. SGR 1900+14

Advanced

Download all Circulars as a .tar.gz archive:
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