Skip to main content
Retirement of GCN Classic VOEvent Brokers. 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. IPN localization of GRB000811
  2. GRB000801, Gamma Ray Observations
  3. GRB000801, VLT-Antu R-band observations
  4. GRB000301C, UBVI optical observations
  5. GRB000801, Radio Observations
  6. GRB 991208 Host Galaxy Imaging
  7. Updated IPN coordinates for GRB000801
  8. IPN localization of GRB000801
  9. IPN localization of GRB000801
  10. IPN localization of GRB000730B
  11. IPN localization of GRB000730B
  12. IPN localization of GRB000730
  13. GRB 990510: Possible detection of a host galaxy
  14. GRB 990510 Host Galaxy Discovery
  15. GRB 000727, optical observations
  16. IPN localization of GRB000727
  17. GRB 990705, HST/STIS observations of the host galaxy
  18. GRB 990712: Late time HST/STIS Observations
  19. GRB 991216, HST/STIS observations
  20. GRB000620, Radio Observations
  21. GRB981226, HST/STIS observations of the host galaxy
  22. GRB000630, optical observations
  23. GRB 000630: Detection of the Optical Afterglow
  24. GRB000630, Revised BVRI Field Photometry
  25. GRB000630, Optical Observations
  26. GRB000630, optical observations
  27. GRB000630, optical observations
  28. GRB000630, BVRI Field Photometry
  29. GRB000630, optical observations
  30. GRB000630, optical observations
  31. GRB000630: Optical observations
  32. GRB000630, Radio Observations
  33. possible optical counterpart of GRB 000630
  34. IPN triangulation of GRB000630
  35. GRB 000623, optical observations
  36. GRB 000620, optical observations
  37. GRB000418, HST/STIS Observations
  38. GRB990123: Late-time HST/STIS observations of the host
  39. GRB 990506, HST/STIS Observations of the Host Galaxy
  40. GRB000623
  41. GRB 000620: J-band observations
  42. GRB000620, optical observations
  43. GRB000615: H-band observations
  44. GRB990308, HST/STIS observations of the host galaxy
  45. GRB000620 - Optical observations
  46. GRB000620 Optical observations
  47. IPN annulus for GRB000620
  48. GRB000620: BeppoSAX WFC and GRBM detection
  49. GRB000615, Radio observations
  50. GRB000607, optical observations
  51. GRB 000615: NIR further observations
  52. GRB000620: refined BeppoSAX/WFC coordinates
  53. BeppoSAX ALERT: GRB000620
  54. GRB000620: BeppoSAX Alert
  55. GRB990123, HST/STIS observations of the host galaxy
  56. GRB000616 optical observations
  57. GRB 000615, near-infrared observations
  58. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  59. GRB000616 [IPN Position]
  60. GRB000615B [IPN Position]
  61. GRB000615, further R-band photometry
  62. GRB 000615: NIR observations
  63. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  64. GRB000615, R-band photometry
  65. GRB000615: BeppoSAX refined coordinates
  66. GRB980425, HST/STIS observations of the host galaxy
  67. GRB000615: BeppoSAX GRB Alert
  68. The Hosts of GRB 980703 and GRB 971214
  69. GRB 000301C: Further Late-Time HST/STIS observations
  70. GRB000528: follow-up X-ray measurements and update of IPN annulus
  71. Optical Follow-up of GRB000529 Error Box
  72. GRB980519, HST/STIS observations of the host galaxy
  73. GRB000607, Radio Observations
  74. BeppoSAX X-ray transient/possible GRB000608
  75. GRB000604 optical non-detection
  76. GRB000604 - Optical observations
  77. GRB000607, A SHORT, HARD BURST
  78. GRB000604, optical observations
  79. GRB000528, optical observations at ESO
  80. GRB 000604 optical observations
  81. GRB 000418: Detection of the Host Galaxy
  82. GRB000604, optical observations, comparison with DPOSS
  83. GRB000604 [IPN Position]
  84. GRB000528, Radio Observations
  85. X-ray Afterglow of GRB 000529
  86. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  87. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  88. GRB000529: Optical Observations
  89. IPN localization and time history of GRB000528
  90. New IPN localization of GRB000529
  91. GRB000519: Optical observations
  92. IPN localization of GRB000529
  93. GRB 000528 - WFC measurements
  94. GRB000529: BeppoSAX WFC position
  95. GRB000528: BeppoSAX GRBM observations
  96. GRB 000528 Optical Observations
  97. GRB000519, BVRI field photometry
  98. IPN triangulation of GRB000519
  99. IPN triangulation of GRB000516
  100. Re: GRB000508B : Optical observations

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