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"

32784 results found.

  1. IPN triangulation of GRB031120 (two large error boxes)
  2. GRB 031111B (= H2925) : Kyoto Optical Observation
  3. IPN/HETE localization of GRB031109 (=H2917; large error box)
  4. IPN detection of activity from SGR1806-20
  5. GRB 031111, Radio observations
  6. IPN triangulation of GRB031114 (large error box)
  7. IPN triangulation of GRB031107 (two large error boxes)
  8. GRB 031111: Optical observations
  9. GRB 031111, optical observations
  10. SN 2003jd (SN/GRB?) -- X-ray Observations
  11. HETE Prompt GRB Spectral Analyses
  12. IPN triangulation of GRB031111 (=H2924): small error box
  13. IPN triangulation of GRB031108 (large error box)
  14. GRB030929/SN2003jd association unlikely based on IPN localiztion
  15. IPN triangulation of GRB031027 (small error box)
  16. IPN triangulation of GRB031026B (large error box)
  17. SN 2003jd (SN/GRB?), Radio Observations
  18. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  19. GRB 031026: Further Ic Observations
  20. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  21. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  22. IPN triangulation of GRB031024 (single error box)
  23. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  24. GRB 031026: Ic Observations
  25. GRB031026 : KISO optical follow-up observation
  26. IPN triangulation of GRB031024 (annulus)
  27. IPN triangulation of GRB031020 (large error box)
  28. IPN triangulation of GRB031016 (two large error boxes)
  29. IBAS alert 1180 refers to a burst from SGR 1806-20
  30. HETE Prompt GRB Light Curves and Color-Color Diagrams
  31. IPN triangulation of GRB031014 (annulus)
  32. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  33. IPN triangulation of GRB031008 (annulus)
  34. IPN detection of continued activity from SGR1806-20
  35. IPN triangulation of GRB031007 (two large error boxes)
  36. XRF 030723: Subaru Optical Observations
  37. IPN triangulation of GRB031004B (annulus)
  38. IPN triangulation of GRB031004A (short/hard; annulus)
  39. IPN triangulation of GRB030929 (short/hard; annulus)
  40. XRF 030824: Early follow-up observation at Kiso observatory
  41. XRF 030824: observations at CFHT
  42. IPN triangulation of GRB030926 (short/hard; large error box)
  43. IPN triangulation of GRB030922B (large error box)
  44. IPN triangulation of GRB030922A (large error box)
  45. IPN triangulation of GRB030921 (large error box)
  46. IPN triangulation of GRB030919 (large error box)
  47. GRB030922 triangulation (annulus)
  48. GRB030913: Subaru Optical Observations
  49. GRB 030913: ROTSE-3c Optical Observations
  50. GRB030913: OT's limit by MASTER
  51. GRB030921 triangulation (annulus)
  52. GRB030913, candidate afterglow observations
  53. GRB 030913, optical candidate
  54. GRB 030913, BOOTES observations
  55. IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
  56. GRB030913 (=H2849): TAROT Observations
  57. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  58. Magellan Observations of GRB030725 (=H2779)
  59. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  60. IPN triangulation of GRB030908 (annulus)
  61. GRB 030913: Optical limit at RIKEN
  62. XRF030824: Optical observations
  63. IPN triangulation of GRB030903 (large error box)
  64. IPN triangulation of GRB030831 (annulus)
  65. IPN triangulation of GRB030830 (large error box)
  66. GRB 030824: Candidate Follow-Up
  67. IPN triangulation of GRB030827 (large error box)
  68. GRB 030823 observation at Ouda
  69. XRF030824: Second-epoch Palomar observations
  70. IPN triangulation of GRB030822 (annulus)
  71. GRB030823: Palomar observations
  72. XRF030824: Palomar observations
  73. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  74. IPN triangulation of GRB030821 (=H2814; refined error box)
  75. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  76. Summary of recent IPN and HETE detections of SGR bursts
  77. IPN triangulation of GRB030814 (annulus)
  78. IPN detection of continued activity from SGR1806-20
  79. 030813 SGR event (Konus-Wind observation)
  80. GRB 030817 = H2808 TAROT optical observations
  81. SGR 1808-20 (=H2802): A Possible new SGR
  82. GRB 021206 Optical Observations
  83. IPN triangulation of GRB030808 (two large error boxes)
  84. IPN triangulation of GRB030806 (large burst; large error box)
  85. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  86. IPN/HETE summary of recent bursts from SGR1806-20
  87. XRF 030723: Detection of a rebrightening in the optical afterglow
  88. GRB030725: Optical observations
  89. XRF030723, BVRcIc field photometry update
  90. IPN triangulation of GRB030801 (large error box)
  91. GRB021206 optical counterpart upper limit
  92. IPN triangulation of GRB030731 (annulus)
  93. IBAS GRB Alerts 1011-1017 NOT CONFIRMED
  94. IPN triangulation of GRB030725 (=H2779; small error box)
  95. XRF030723 (=H2777): Second Epoch Magellan Observations
  96. GRB 030725: optical observations.
  97. GRB030725, optical transient observations
  98. IPN triangulation of GRB030726 (large error box)
  99. IPN triangulation of GRB030722 (large error box)
  100. IPN triangulation of GRB030721 (large error box)

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