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"

24754 results found.

  1. GRB 991216--Summary of RXTE Observations
  2. GRB 991216 Optical Observations
  3. GRB 991216, optical observations
  4. GRB 991208 SAO-RAS Spectroscopy
  5. SAX J2303.2+0015: an x-ray/GRB?
  6. GRB 991216, Optical Transient
  7. GRB991216 ('Beethoven Burst') B, R, and K Observations
  8. GRB991216, infrared observations
  9. GRB 991208 optical observations
  10. GRB 991216 Optical Observation
  11. GRB 991216: Extremely bright BATSE burst
  12. R-band Observations of GRB991208 at TNG
  13. GRB991208, optical observations
  14. GRB 991208, Optical Observation
  15. GRB991208, optical observations
  16. GRB 991208 optical observations
  17. Optical Observations of GRB991105
  18. GRB991106: BeppoSAX/BATSE results
  19. GRB991106, near-infrared observations
  20. BeppoSAX NFI Observation of GRB991106
  21. GRB 991106, radio observations
  22. GRB991106: the first BeppoSAX short GRB detection?
  23. GRB 991105: BATSE Observations
  24. GRB 991106 Optical Observations
  25. GRB991106, optical observation at SAO-RAS
  26. GRB 991106, LOTIS Optical Observations
  27. GRB991105: SAX-GRBM/-WFC detection
  28. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  29. GRB 991014, Optical Observations
  30. GRB 991014 - BeppoSAX NFI observations
  31. GRB 991014, radio observations
  32. GRB 991014, Optical Observations
  33. GRB 991014, optical observations
  34. GRB 990915 optical observations
  35. Optical Observations of GRB990907
  36. GRB990907: BeppoSAX follow up and X-ray afterglow
  37. GRB990907 and 990908
  38. GRB 990712 Late Optical Decay and Host Galaxy
  39. GRB990806 BeppoSAX follow up
  40. GRB990806: BATSE Observations
  41. GRB 990806 Optical observations
  42. GRB 990806, Optical Observations
  43. GRB 990806, optical observations
  44. GRB 990806, Optical Observations
  45. GRB990806 UBVRIJHK observations
  46. GRB 990712 Optical Observations
  47. GRB 990712
  48. Late-time HST/STIS Observations of GRB 990510
  49. BeppoSAX NFI Observation of GRB990705
  50. BeppoSAX NFI Observation of GRB990705
  51. GRB 990705, R-band observations
  52. Infrared and Optical Observations of GRB990705
  53. GRB990704: SAX-NFI results summary
  54. GRB990704 radio and optical observations
  55. GRB990704
  56. GRB990704, optical observations
  57. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  58. Optical Observations of GRB990627
  59. BeppoSAX: GRB990625
  60. Late-time HST/STIS Observation of GRB 990123
  61. Optical Observations of GRB 990506
  62. GRB990527 Optical Observations
  63. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  64. Late Afterglows of GRBs 990510, 990123
  65. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  66. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  67. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  68. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  69. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  70. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  71. radio observations of X-ray/GRB transient field
  72. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  73. Optical report on X-ray/GRB transient
  74. radio detection of X-ray/GRB transient
  75. BeppoSAX: A new fast X-ray transient
  76. GRB 990510: optical observations
  77. GRB 990510: optical linear polarization
  78. GRB 990510: optical observations
  79. GRB990510: X-ray afterglow
  80. GRB 990510: Broad Band Break
  81. GRB 990510: BATSE Observations
  82. GRB 990510: BeppoSAX/GRBM observations
  83. GRB990510 optical observations
  84. GRB 990510 optical observations
  85. GRB 990506 Radio Observations
  86. GRB 990123, optical monitoring
  87. GRB 990506: BATSE Observations
  88. GRB 990506, optical observations
  89. GRB 990506, Optical Observations
  90. GRB 990506 optical observations
  91. GRB 990506, optical observations
  92. GRB 990506, armchair astronomy
  93. GRB 990506, optical observations from +1 to +3 hours
  94. GRB 990506, optical observations
  95. GRB990506 observation plan
  96. IPN localization for GRB990506
  97. GRB990323 PRECISE IPN POSITION
  98. GRB 990316 Optical Observations
  99. GRB 990316 optical observations
  100. GRB990316: simultaneous optical observation

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