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"

28049 results found.

  1. GRB 991208: HST Imaging of the Host Galaxy
  2. GRB 001025B, I-band observations
  3. XMM-Newton observation of GRB001025
  4. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  5. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  6. GRB001007: Optical observations
  7. ASM Localization of GRB 001025
  8. GRB001007, Radio observations
  9. GRB 001018, Possible Radio Afterglow
  10. GRB001018, Gamma Ray Observations
  11. IPN TRIANGULATION OF GRB001019
  12. IPN TRIANGULATION OF GRB001018
  13. IPN TRIANGULATION OF GRB 001017
  14. V,R,I band observations of GRB000926
  15. HETE positions added to GCN
  16. GRB000926 - Amateur Optical Observations
  17. CONCAM null result on GRB001005
  18. IPN triangulation of GRB001005
  19. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  20. GRB000926 - Optical observations
  21. GRB000926 - Optical observations
  22. GRB 000926, Optical Decay
  23. GRB000911: VLT infrared observation
  24. GRB 000926, Optical Observations
  25. GRB000926 K'-band Observation
  26. J and K band observations of GRB 000926
  27. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  28. CONCAM crude optical limits before and after GRB000926
  29. GRB 000926: Preliminary R-band Lightcurve
  30. Spectroscopic Redshift of GRB 000926
  31. GRB 000926: Optical candidate
  32. Optical candidate for GRB000926
  33. GRB 000911, BVRI field photometry
  34. GRB000911, Radio and Optical observations
  35. GRB000911: Optical observations
  36. GRB000830, BVRI field photometry
  37. GRB000210, Optical observations
  38. "Snapshot" afterglow IDs and GRB 000830
  39. GRB000730, Gamma Ray Observations
  40. GRB000812, Radio observations
  41. GRB000801, Gamma Ray Observations
  42. GRB000801, VLT-Antu R-band observations
  43. GRB 991208 Host Galaxy Imaging
  44. IPN localization of GRB000730B
  45. GRB 990510: Possible detection of a host galaxy
  46. GRB 990510 Host Galaxy Discovery
  47. IPN localization of GRB000727
  48. GRB 990712: Late time HST/STIS Observations
  49. GRB 991216, HST/STIS observations
  50. GRB000620, Radio Observations
  51. GRB000630, optical observations
  52. GRB000630, Revised BVRI Field Photometry
  53. GRB000630, Optical Observations
  54. GRB000630, optical observations
  55. GRB000630, optical observations
  56. GRB000630, BVRI Field Photometry
  57. GRB000630, optical observations
  58. GRB000630: Optical observations
  59. GRB000630, Radio Observations
  60. possible optical counterpart of GRB 000630
  61. GRB 000620, optical observations
  62. GRB000418, HST/STIS Observations
  63. GRB990123: Late-time HST/STIS observations of the host
  64. GRB000620, optical observations
  65. GRB000615: H-band observations
  66. GRB990308, HST/STIS observations of the host galaxy
  67. GRB000620 - Optical observations
  68. GRB000620 Optical observations
  69. GRB000620: BeppoSAX WFC and GRBM detection
  70. GRB000607, optical observations
  71. GRB 000615: NIR further observations
  72. GRB990123, HST/STIS observations of the host galaxy
  73. GRB000616 optical observations
  74. GRB 000615, near-infrared observations
  75. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  76. GRB000615, further R-band photometry
  77. GRB 000615: NIR observations
  78. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  79. GRB000615, R-band photometry
  80. The Hosts of GRB 980703 and GRB 971214
  81. GRB 000301C: Further Late-Time HST/STIS observations
  82. GRB000528: follow-up X-ray measurements and update of IPN annulus
  83. GRB980519, HST/STIS observations of the host galaxy
  84. GRB000604 optical non-detection
  85. GRB000604 - Optical observations
  86. GRB000604, optical observations
  87. GRB000528, optical observations at ESO
  88. GRB 000604 optical observations
  89. GRB 000418: Detection of the Host Galaxy
  90. GRB000604, optical observations, comparison with DPOSS
  91. GRB000528, Radio Observations
  92. X-ray Afterglow of GRB 000529
  93. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  94. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  95. GRB 000528 - WFC measurements
  96. GRB000519, BVRI field photometry
  97. IPN triangulation of GRB000519
  98. GRB000508B, optical photometry
  99. GRB000508B, BVR field photometry
  100. Possible GRB-related phenomenon

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