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"

26497 results found.

  1. HETE positions added to GCN
  2. GRB001011 BeppoSAX/WFC refined position
  3. GRB 001007, BVR-band observations
  4. GRB000926 - Amateur Optical Observations
  5. GRB001007: Optical observations
  6. CONCAM null result on GRB001005
  7. IPN triangulation of GRB001007
  8. HETE-2 Launches Successfully
  9. HETE-2 48 hour Launch Delay
  10. GRB 000926 Chandra Observation
  11. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  12. GRB000926 - Optical observations
  13. GRB000926 - Optical observations
  14. GRB 000926, Optical Decay
  15. GRB 000926, Optical Observations
  16. GRB000926 K'-band Observation
  17. J and K band observations of GRB 000926
  18. GRB 000926, optical observation by Oksanen (vsnet-grb)
  19. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  20. CONCAM crude optical limits before and after GRB000926
  21. Spectroscopic Redshift of GRB 000926
  22. GRB 000926: Optical candidate
  23. Optical candidate for GRB000926
  24. IPN triangulation of GRB000926
  25. GRB 000911, BVRI field photometry
  26. IPN triangulation of GRB000925
  27. GRB000911, Radio and Optical observations
  28. GRB000911: Optical observations
  29. IPN triangulation of GRB000911
  30. IPN triangulation of GRB000910
  31. GRB000830, BVRI field photometry
  32. IPN triangulation of GRB000830
  33. HST/STIS observations of the host galaxy of GRB 980329
  34. IPN localization of GRB000820
  35. SGR 1806-20 burst activity
  36. GRB000801 & GRB000730, Gamma Ray Observations
  37. GRB000730, Gamma Ray Observations
  38. IPN localization of GRB000812
  39. IPN localization of GRB000811
  40. GRB000801, Gamma Ray Observations
  41. GRB000801, VLT-Antu R-band observations
  42. GRB 991208 Host Galaxy Imaging
  43. IPN localization of GRB000801
  44. IPN localization of GRB000730B
  45. IPN localization of GRB000730B
  46. IPN localization of GRB000730
  47. GRB 990510: Possible detection of a host galaxy
  48. GRB 990510 Host Galaxy Discovery
  49. IPN localization of GRB000727
  50. GRB 990705, HST/STIS observations of the host galaxy
  51. GRB 990712: Late time HST/STIS Observations
  52. GRB 991216, HST/STIS observations
  53. GRB000630, optical observations
  54. GRB000630, Revised BVRI Field Photometry
  55. GRB000630, Optical Observations
  56. GRB000630, optical observations
  57. GRB000630, optical observations
  58. GRB000630, BVRI Field Photometry
  59. GRB000630, optical observations
  60. GRB000630: Optical observations
  61. possible optical counterpart of GRB 000630
  62. IPN triangulation of GRB000630
  63. GRB 000620, optical observations
  64. GRB000418, HST/STIS Observations
  65. GRB990123: Late-time HST/STIS observations of the host
  66. GRB 990506, HST/STIS Observations of the Host Galaxy
  67. GRB000623
  68. GRB 000620: J-band observations
  69. GRB000620, optical observations
  70. GRB990308, HST/STIS observations of the host galaxy
  71. GRB000620 - Optical observations
  72. GRB000620 Optical observations
  73. GRB000620: BeppoSAX WFC and GRBM detection
  74. GRB000607, optical observations
  75. GRB 000615: NIR further observations
  76. GRB990123, HST/STIS observations of the host galaxy
  77. GRB000616 optical observations
  78. GRB 000615, near-infrared observations
  79. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  80. GRB000616 [IPN Position]
  81. GRB000615B [IPN Position]
  82. GRB000615, further R-band photometry
  83. GRB 000615: NIR observations
  84. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  85. GRB000615, R-band photometry
  86. GRB000615: BeppoSAX refined coordinates
  87. GRB980425, HST/STIS observations of the host galaxy
  88. GRB 000301C: Further Late-Time HST/STIS observations
  89. GRB000528: follow-up X-ray measurements and update of IPN annulus
  90. BeppoSAX X-ray transient/possible GRB000608
  91. GRB000604 - Optical observations
  92. GRB000607, A SHORT, HARD BURST
  93. GRB000604, optical observations
  94. GRB000528, optical observations at ESO
  95. GRB 000418: Detection of the Host Galaxy
  96. GRB000604, optical observations, comparison with DPOSS
  97. GRB000604 [IPN Position]
  98. GRB000528, Radio Observations
  99. X-ray Afterglow of GRB 000529
  100. GRB000529: BeppoSAX NFI follow-up preliminary analysis

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