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"
  1. GRB030329 - Light curve flattening
  2. GRB 030329: SARA Optical Observations
  3. GRB 030324, optical search
  4. GRB030329 - near contemporaneous optical limits from CONCAM
  5. GRB030329: R and B observations
  6. GRB 030329, optical observations
  7. GRB030329: Optical observations
  8. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  9. GRB030329a: detection by Konus-Wind
  10. GRB030329b: detection by Konus-Wind and Helicon-CoronasF
  11. GRB 030329: Light curve observed during the change of its slope.
  12. GRB030329, BVRcIc field photometry
  13. GRB030329, SPM optical observations
  14. GRB 030329: Optical Decay
  15. Redshift of GRB 030329
  16. GRB030329: ROTSE network observes steepening of decay curve
  17. GRB 030329, optical photometry
  18. GRB 030329: Optical decay and synthesis
  19. GRB030329 optical observations
  20. GRB030329: optical spectroscopy with the TNG
  21. GRB 030329: Radio Observations
  22. GRB 030329, optical spectroscopy
  23. GRB 030329: still bright
  24. GRB 030329: Optical pre-Imaging
  25. GRB 030329: visual observations
  26. GRB 030329: Upper limit from 5.6 hours before trigger
  27. GRB030328: R optical observation
  28. GRB030328: X-ray Afterglow Observed with Chandra
  29. GRB 030323: Gemini South VRI obsevations.
  30. GRB030329: Optical observations
  31. GRB 030329, R-band observations, supplement
  32. GRB030329 optical observations
  33. GRB030329:optical observations by MASTER
  34. GRB 030329: optical observations
  35. GRB 030329, R-band observations
  36. GRB 030329: OT B and R photometry, decline rate
  37. GRB030329: Upper limits from recent and historical observations.
  38. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  39. RXTE detection of GRB 030329 afterglow
  40. GRB 030329: Optical Afterglow Observations
  41. GRB 030329: precise position from Kyoto images
  42. GRB 030328 Optical Observations
  43. GRB030328: Decay index
  44. GRB 030328: Optical observations
  45. GRB 030328: optical observations
  46. GRB 030329: Optical afterglow fading
  47. GRB 030329 follow-up
  48. GRB 030329: Optical afterglow candidate
  49. GRB 030329: OT candidate
  50. GRB 030329: Optical afterglow candidate
  51. GRB 030328: OT photometry
  52. GRB030328: optical spectroscopy at TNG
  53. GRB030328: optical photometry at the TNG
  54. VLT spectra of GRB 030328
  55. GRB 030328, optical spectroscopy
  56. GRB 030328, optical observations
  57. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  58. GRB 030328: Optical observations
  59. Re: GRB 030328: Finding chart
  60. GRB 030328: Finding chart
  61. GRB 030328: Optical afterglow candidate
  62. GRB030323 optical observations
  63. GRB030324 optical observation
  64. GRB030131, BVRcIc field photometry
  65. Possible GRB030323 localized by INTEGRAL
  66. IPN triangulation of GRB030325 (final analysis)
  67. GRB030323: Detection on 2003/03/24
  68. IPN triangulation of GRB030326 (single small error box)
  69. GRB 030323: SARA Optical Observations
  70. IPN triangulation of GRB030325 (single small error box)
  71. GRB030324, optical observations
  72. GRB030324, optical observations
  73. IPN triangulation of GRB030325 (two small error boxes)
  74. GRB 030324: TAROT optical observations
  75. GRB030323: V, R, I photometry
  76. GRB 030324 (HETE #2641): Optical observations
  77. GRB030324, Optical Observations
  78. GRB030323: Upper limits from recent and historical observations.
  79. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  80. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  81. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  82. VLT/FORS2 spectra of GRB 030323
  83. GRB030323, ROTSE-III detection of possible optical counterpart
  84. GRB030323, optical observations
  85. GRB030324, BVRcIc field photometry
  86. GRB030323, possible optical counterpart
  87. GRB030323, BVRcIc field calibration
  88. GRB 030324 optical observations
  89. GRB 030320: Optical Observations
  90. GRB 030324, optical observations
  91. IPN triangulation of GRB030320B (annulus)
  92. IPN triangulation of GRB030320 (small error box)
  93. IPN triangulation of GRB030320
  94. Possible GRB 030320 localized by INTEGRAL
  95. GRB030226, addendum to GCN 1892
  96. IPN upper limit to a GRB associated with SN2003L
  97. IPN triangulation of GRB030317 (annulus)
  98. IPN triangulation of GRB030307 (annulus)
  99. GRB 030227: Optical limit at RIKEN
  100. GRB 030226 Optical observations

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