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"

10762 results found.

  1. Increase of SGR 1806-20 activity
  2. GRB 040812: Optical counterparts of CXO sources
  3. Bursting activity from SGR 1806-20 detected with IBAS
  4. Konus-Wind observation of GRB040810 (=H3489)
  5. GRB 040812: a long GRB detected by INTEGRAL
  6. GRB 040730: Optical observations
  7. GRB 040730: a long GRB detected with INTEGRAL
  8. Ongoing activity of SGR 1806-20
  9. XRF 040701 - optical observations of the decaying Chandra source
  10. XRF040701: Second-Epoch Chandra Observations
  11. Cancellation of IBAS/INTEGRAL GRB alerts
  12. XRF040701: VLA Observations
  13. XRF040701: First-Epoch Chandra Observations
  14. GRB040709 J,H-band observations
  15. GRB040706:observation at University of Miyazaki
  16. GRB 040624: optical observations
  17. GRB 040624: R-band observations
  18. GRB 040624 - A long GRB detected with INTEGRAL
  19. IPN Summary of SGR1806-20 Activity in 2004
  20. SGR 1806-20: no IR variability of the proposed counterparts
  21. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  22. SGR 1806-20, potential NIR counterpart
  23. MASTER: HETE Alert 3274 optical observation
  24. Activivty of SGR 1806-20
  25. IPN triangulation of an intense intermediate burst from SGR1806-20
  26. IBAS GRB Alerts n.1785 to 1791
  27. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  28. GRB 040511: Second Epoch Optical Observations
  29. GRB 040511: Optical Observations
  30. GRB040511: Optical Observations
  31. GRB and XRF on April 27, 2004. Detection by Konus-Wind and Helicon (Coronas-F)
  32. IPN triangulation of GRB040425 (=H3183)
  33. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  34. GRB 040422: a long GRB detected with INTEGRAL
  35. GRB 040403, deep optical observations
  36. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  37. GRB 040403: Optical observations
  38. GRB 040403: a long GRB detected with INTEGRAL
  39. Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
  40. GRB 040329: hard burst detected by Konus-Wind and Helicon - Coronas-F
  41. IBAS GRB Alert 1694
  42. GRB040323: NIR Observations and Variable Object
  43. GRB 040323: a long GRB detected with INTEGRAL
  44. IBAS GRB alerts 1679, 1680, 1681
  45. GRB040223: Deep NIR NTT data re-analysis
  46. GRB 031203: spectoscopic evidence for a 1998bw-like SN
  47. MASTER: RXTE GRB040308 optical observation
  48. IBAS results on a burst from SGR1806-20
  49. INTEGRAL detection of activity from SGR1806-20
  50. IPN triangulation of GRB040228 (H3066, H3067)
  51. GRB 040223: further offline analysis
  52. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  53. GRB040106, likely optical afterglow
  54. GRB031220: observation at Univercity of Miyazaki
  55. GRB 040106 : peak flux
  56. IPN triangulation of an intermediate burst from SGR1806-20
  57. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  58. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  59. GRB031220: Palomar Observations
  60. GRB 031220: Subaru observation
  61. GRB 031220: Optical observation at Tokyo Tech
  62. GRB031220: ROTSE-IIIb Optical Limits
  63. GRB031220 : Optical Observation of Lulin Observatory
  64. GRB 2974 follow-up observations
  65. GRB 021203: A Normal GRB viewed far off axis?
  66. GRB 031203: Variable Radio Source
  67. GRB 031203: Optical/IR Astrometry
  68. GRB 031203: Deep NIR NTT & VLT observations
  69. GRB 031203: Radio detection
  70. IPN triangulation of GRB031127A and B (quasi-simultaneous; large error boxes)
  71. GRB 031203: further analysis of INTEGRAL data
  72. GRB 031203: A long GRB detected with INTEGRAL
  73. IPN/HETE localization of GRB031109 (=H2917; large error box)
  74. IPN detection of activity from SGR1806-20
  75. IPN triangulation of GRB031107 (two large error boxes)
  76. HETE Prompt GRB Spectral Analyses
  77. XRF031109 (=H2919): A very long XRF localized by HETE
  78. Lulin optical follow-up observations of GRB031026
  79. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  80. IBAS alert 1180 refers to a burst from SGR 1806-20
  81. Ongoing Bursting Activity from SGR 1806-20 detected with IBAS
  82. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  83. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  84. IPN detection of continued activity from SGR1806-20
  85. A burst from SGR 1806-20 detected with IBAS
  86. IPN triangulation of GRB030926 (short/hard; large error box)
  87. IPN triangulation of GRB030922B (large error box)
  88. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  89. IPN triangulation of GRB030921 (large error box)
  90. IPN triangulation of GRB030919 (large error box)
  91. GRB 030913, optical candidate
  92. GRB030913: AAVSO optical observations
  93. GRB030913 (=H2849): TAROT Observations
  94. XRF030824: Optical observations
  95. IPN triangulation of GRB030903 (large error box)
  96. IBAS detection of bursts from SGR 1806-20
  97. Radio Observations of SGR1806-20
  98. IPN triangulation of GRB030831 (annulus)
  99. IPN triangulation of GRB030830 (large error box)
  100. INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS

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