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"

32510 results found.

  1. GRB 991106, optical observations
  2. Revised BeppoSAX WFC position of GRB991105
  3. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  4. GRB 991014, Optical Observations
  5. GRB 991014 - BeppoSAX NFI observations
  6. GRB 991014, Optical Observations
  7. GRB 991014, Optical Observations
  8. GRB 991014, optical observations
  9. Super-LOTIS optical observation of GRB991014
  10. IPN/NFI error box for GRB991014
  11. IPN localization of GRB991014 - CORRECTION
  12. IPN localization of GRB991014
  13. GRB 990915 optical observations
  14. GRB 990907 optical observations
  15. Optical Observations of GRB990907
  16. IPN error box for GRB990915 (=BATSE 7766)
  17. IPN localization of BATSE #7766 (GRB990915)
  18. GRB990907: BeppoSAX follow up and X-ray afterglow
  19. GRB990907 and 990908
  20. IPN localization of GRB990907
  21. GRB 990712 Late Optical Decay and Host Galaxy
  22. GRB 990712, Optical Observation
  23. GRB990806 BeppoSAX follow up
  24. GRB990806: BATSE Observations
  25. GRB 990806 Optical observations
  26. Optical Observations of GRB990806
  27. GRB 990806, Optical Observations
  28. GRB 990806, optical observations
  29. GRB 990806, Optical Observations
  30. GRB990806 UBVRIJHK observations
  31. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  32. VLT spectrum of GRB990712
  33. GRB 990712
  34. Late-time HST/STIS Observations of GRB 990510
  35. BeppoSAX NFI Observation of GRB990705
  36. BeppoSAX NFI Observation of GRB990705
  37. Updated Astrometry for the IR Counterpart of GRB990705
  38. GRB 990705, R-band observations
  39. Updated IPN localization of GRB990705
  40. IPN localization of GRB990704
  41. IPN localization of GRB990705
  42. Infrared and Optical Observations of GRB990705
  43. GRB 990705, radio observations
  44. GRB990704: SAX-NFI results summary
  45. GRB990704 radio and optical observations
  46. GRB 990704 X-ray Observations
  47. GRB 990704 Optical Observations
  48. GRB 990704, optical observations
  49. GRB990704
  50. GRB990704
  51. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  52. GRB990704, optical observations
  53. GRB990704: possible X-ray afterglow
  54. Identification of a possible optical counterpart for GRB990704
  55. GRB990704
  56. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  57. Optical Observations of GRB990627
  58. GRB 990627, radio observations
  59. GRB990627: BeppoSAX-WFC final location
  60. GRB 990506 - clarification to GCN 352
  61. GRB 990506 - Optical Observations
  62. Optical Observations of GRB 990506
  63. GRB 990506 Radio Transient
  64. GRB990527 Optical Observations
  65. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  66. Late Afterglows of GRBs 990510, 990123
  67. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  68. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  69. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  70. GRB 990506 optical observation
  71. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  72. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  73. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  74. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  75. radio observations of X-ray/GRB transient field
  76. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  77. Optical report on X-ray/GRB transient
  78. radio detection of X-ray/GRB transient
  79. BeppoSAX: A new fast X-ray transient
  80. GRB 990510: optical observations
  81. GRB990510, VI observations
  82. GRB 990506 R band observations
  83. GRB990510: X-ray afterglow
  84. VLT spectrum of GRB990510
  85. GRB 990510: Broad Band Break
  86. GRB 990510: BATSE Observations
  87. GRB990510: optical observation
  88. GRB 990510 Optical Observations
  89. GRB 990510, BVI photometry
  90. GRB 990510 optical observations
  91. GRB990510 optical observations
  92. GRB990510
  93. GRB 990510 optical observations
  94. GRB 990510 optical observations
  95. Galactic extinction towards GRB 990510
  96. IPN localization of GRB990510
  97. GRB 990506 Radio Observations
  98. GRB 990506: BATSE Observations
  99. GRB 990506, optical observations
  100. GRB 990506, 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