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"

18024 results found.

  1. IPN TRIANGULATION OF GRB010109
  2. IPN triangulation of GRB010104
  3. IPN triangulation of GRB010103
  4. IPN triangulation of GRB001219
  5. GRB 001212 Optical Observation
  6. GRB 001212 Optical Observation
  7. GRB 001212 possible OA
  8. IPN triangulation of GRB001212
  9. Confirmation of IPN position for GRB001204
  10. IPN triangulation of GRB001204 (short/hard)
  11. GRB001120, optical observations
  12. WSRT 4.8 GHz observations of GRB001109
  13. IPN triangulation of GRB001120
  14. GRB 001109: deep JHK upper limits
  15. GRB 001109 X-ray afterglow with BeppoSAX
  16. CORRECTION to XMM-Newton observation of GRB001025
  17. GRB001109, Radio observations
  18. BeppoSAX ALERT: GRB001109
  19. GRB001105 BVRI field photometry correction
  20. GRB001105, BVRI field photometry
  21. IPN TRIANGULATION OF GRB001105
  22. GRB 001025B, Optical obervations
  23. GRB 991208: HST Imaging of the Host Galaxy
  24. GRB 001025B, I-band observations
  25. XMM-Newton observation of GRB001025
  26. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  27. GRB001007: Optical observations
  28. ASM Localization of GRB 001025
  29. GRB001007, Radio observations
  30. IPN TRIANGULATION OF GRB001019
  31. IPN TRIANGULATION OF GRB001018
  32. IPN TRIANGULATION OF GRB 001017
  33. V,R,I band observations of GRB000926
  34. HETE positions added to GCN
  35. GRB 001007, BVR-band observations
  36. GRB000926 - Amateur Optical Observations
  37. CONCAM null result on GRB001005
  38. IPN triangulation of GRB001007
  39. GRB000926 - Optical observations
  40. GRB000926 - Optical observations
  41. GRB 000926, Optical Observations
  42. GRB000926 K'-band Observation
  43. J and K band observations of GRB 000926
  44. GRB000911 Optical Observations
  45. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  46. CONCAM crude optical limits before and after GRB000926
  47. GRB 000926: Optical candidate
  48. Optical candidate for GRB000926
  49. IPN triangulation of GRB000926
  50. GRB 000911, BVRI field photometry
  51. GRB000911, Radio and Optical observations
  52. GRB000911: Optical observations
  53. IPN triangulation of GRB000910
  54. GRB000830, BVRI field photometry
  55. GRB000801, VLT-Antu R-band observations
  56. GRB000301C, UBVI optical observations
  57. GRB000801, Radio Observations
  58. GRB 991208 Host Galaxy Imaging
  59. IPN localization of GRB000730B
  60. IPN localization of GRB000730B
  61. GRB 990510: Possible detection of a host galaxy
  62. GRB 990510 Host Galaxy Discovery
  63. GRB 990712: Late time HST/STIS Observations
  64. GRB 991216, HST/STIS observations
  65. GRB000630, optical observations
  66. GRB000630, Revised BVRI Field Photometry
  67. GRB000630, Optical Observations
  68. GRB000630, optical observations
  69. GRB000630, optical observations
  70. GRB000630, BVRI Field Photometry
  71. GRB000630, optical observations
  72. GRB000630: Optical observations
  73. possible optical counterpart of GRB 000630
  74. GRB 000620, optical observations
  75. GRB000418, HST/STIS Observations
  76. GRB990123: Late-time HST/STIS observations of the host
  77. GRB000620, optical observations
  78. GRB000620 - Optical observations
  79. GRB000620 Optical observations
  80. GRB000620: BeppoSAX WFC and GRBM detection
  81. GRB000615, Radio observations
  82. GRB000607, optical observations
  83. GRB 000615: NIR further observations
  84. GRB000616 optical observations
  85. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  86. GRB000615, further R-band photometry
  87. GRB 000615: NIR observations
  88. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  89. GRB000615, R-band photometry
  90. GRB 000301C: Further Late-Time HST/STIS observations
  91. GRB000528: follow-up X-ray measurements and update of IPN annulus
  92. BeppoSAX X-ray transient/possible GRB000608
  93. GRB000604 - Optical observations
  94. GRB000604, optical observations
  95. GRB000528, optical observations at ESO
  96. GRB 000418: Detection of the Host Galaxy
  97. GRB000604, optical observations, comparison with DPOSS
  98. GRB000604 [IPN Position]
  99. GRB000528, Radio Observations
  100. X-ray Afterglow of GRB 000529

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