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"

38412 results found.

  1. GRB031111, optical observations
  2. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  3. GRB031203: Chandra Observations
  4. GRB040106, follow-up radio observations
  5. GRB040106: refined X-ray transient position
  6. Follow-up on IBAS GRB Alert 1379
  7. IBAS GRB alert 1379
  8. SN 2003dh/GRB030329 late-time optical spectroscopy
  9. GRB040106, Radio Observations
  10. GRB040106, likely optical afterglow
  11. GRB040106: Second Epoch Optical Observations
  12. GRB 031220: Optical observations of Chandra X-ray sources
  13. GRB031220: observation at Univercity of Miyazaki
  14. GRB 040106 : Planned XMM-Newton observation
  15. GRB 040106 : peak flux
  16. GRB 040106 : a long GRB detected with INTEGRAL
  17. IPN triangulation of an intermediate burst from SGR1806-20
  18. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  19. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  20. GRB031225a triangulation (annulus)
  21. IPN triangulation of GRB031219 (large error box)
  22. GRB031220: Palomar Observations
  23. GRB 031220 : Kyoto Optical Observation
  24. GRB 031220: Subaru observation
  25. GRB 031220: Optical observation at Tokyo Tech
  26. GRB031220: ROTSE-IIIb Optical Limits
  27. GRB031220 : Optical Observation of Lulin Observatory
  28. IPN triangulation of GRB031214 (short/hard; very intense; small error box)
  29. GRB 2974 follow-up observations
  30. GRB 031203: Discovery of a dust echo
  31. GRB031214 triangulation (annulus), [repost of GCN2487, subject corrected]
  32. GRB030921 triangulation (annulus)
  33. GRB 031203: Variable Radio Source
  34. GRB 031203: Magellan spectrum of possible GRB host
  35. GRB 031203: Optical/IR Astrometry
  36. IPN/HETE localization of GRB031203B (=H2949; large error box)
  37. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  38. XMM-Newton Observation of GRB031203
  39. GRB 031203: Deep NIR NTT & VLT observations
  40. GRB031203: K' Photometry of the likely GRB host
  41. XMM-Newton Observation of GRB031203
  42. GRB 031203: Radio detection
  43. GRB 031203: Further reports on December 4 observations
  44. GRB 031203: IR NTTobservations do not confirm REM detection
  45. GRB031203 : Optical Observation of Lulin Observatory
  46. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  47. GRB031203: Planned XMM-Newton observation II
  48. GRB031203: Optical Observations
  49. GRB 031203 XMM-Newton observation
  50. GRB 031203: Optical/IR SMARTS Observations
  51. GRB031203: Planned XMM-Newton observation
  52. IPN triangulation of GRB031127A and B (quasi-simultaneous; large error boxes)
  53. GRB 031203: further analysis of INTEGRAL data
  54. GRB 031203: A long GRB detected with INTEGRAL
  55. IPN triangulation of GRB031201 (large error box)
  56. IPN triangulation of GRB031130 (large error box)
  57. IPN triangulation of GRB031120 (two large error boxes)
  58. GRB 031111B (= H2925) : Kyoto Optical Observation
  59. IPN/HETE localization of GRB031109 (=H2917; large error box)
  60. IPN detection of activity from SGR1806-20
  61. GRB 031111, Radio observations
  62. IPN triangulation of GRB031114 (large error box)
  63. IPN triangulation of GRB031107 (two large error boxes)
  64. GRB 031111: Optical observations
  65. GRB 031111, optical observations
  66. HETE Prompt GRB Spectral Analyses
  67. IPN triangulation of GRB031111 (=H2924): small error box
  68. XRF031109 (=H2919): A very long XRF localized by HETE
  69. IPN triangulation of GRB031108 (large error box)
  70. GRB030929/SN2003jd association unlikely based on IPN localiztion
  71. IPN triangulation of GRB031027 (small error box)
  72. IPN triangulation of GRB031026B (large error box)
  73. SN 2003jd (SN/GRB?), Radio Observations
  74. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  75. GRB 031026: Further Ic Observations
  76. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  77. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  78. IPN triangulation of GRB031024 (single error box)
  79. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  80. GRB 031026: Ic Observations
  81. GRB031026 : KISO optical follow-up observation
  82. IPN triangulation of GRB031024 (annulus)
  83. IPN triangulation of GRB031020 (large error box)
  84. GRB030329: radio observations at RT-22 (CrAO)
  85. IPN triangulation of GRB031016 (two large error boxes)
  86. IBAS alert 1180 refers to a burst from SGR 1806-20
  87. IPN triangulation of GRB031014 (annulus)
  88. XRF 030824: additional observations at CFHT
  89. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  90. IPN triangulation of GRB031008 (annulus)
  91. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  92. IPN detection of continued activity from SGR1806-20
  93. IPN triangulation of GRB031007 (two large error boxes)
  94. XRF 030723: Subaru Optical Observations
  95. IPN triangulation of GRB031004B (annulus)
  96. IPN triangulation of GRB031004A (short/hard; annulus)
  97. IPN triangulation of GRB030929 (short/hard; annulus)
  98. A burst from SGR 1806-20 detected with IBAS
  99. XRF 030824: Early follow-up observation at Kiso observatory
  100. XRF 030824: observations at CFHT

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