Skip to main content
Circulars over Kafka event name backfill. 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"

24658 results found.

  1. IPN triangulation of GRB001120
  2. GRB 001109: deep JHK upper limits
  3. GRB 001109 X-ray afterglow with BeppoSAX
  4. CORRECTION to XMM-Newton observation of GRB001025
  5. GRB001109, Radio observations
  6. GRB001105 BVRI field photometry correction
  7. GRB001105, BVRI field photometry
  8. IPN TRIANGULATION OF GRB001105
  9. GRB 001025B, Optical obervations
  10. GRB 991208: HST Imaging of the Host Galaxy
  11. GRB 001025B, I-band observations
  12. XMM-Newton observation of GRB001025
  13. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  14. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  15. GRB001007: Optical observations
  16. ASM Localization of GRB 001025
  17. GRB001007, Radio observations
  18. GRB 001018, Possible Radio Afterglow
  19. GRB001018, Gamma Ray Observations
  20. IPN TRIANGULATION OF GRB001019
  21. IPN TRIANGULATION OF GRB001018
  22. IPN TRIANGULATION OF GRB 001017
  23. V,R,I band observations of GRB000926
  24. HETE positions added to GCN
  25. GRB000926 - Amateur Optical Observations
  26. CONCAM null result on GRB001005
  27. IPN triangulation of GRB001005
  28. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  29. GRB000926 - Optical observations
  30. GRB000926 - Optical observations
  31. GRB 000926, Optical Decay
  32. GRB000911: VLT infrared observation
  33. GRB 000926, Optical Observations
  34. GRB000926 K'-band Observation
  35. J and K band observations of GRB 000926
  36. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  37. CONCAM crude optical limits before and after GRB000926
  38. GRB 000926: Preliminary R-band Lightcurve
  39. Spectroscopic Redshift of GRB 000926
  40. GRB 000926: Optical candidate
  41. Optical candidate for GRB000926
  42. GRB 000911, BVRI field photometry
  43. GRB000911, Radio and Optical observations
  44. GRB000911: Optical observations
  45. GRB000830, BVRI field photometry
  46. GRB000210, Optical observations
  47. "Snapshot" afterglow IDs and GRB 000830
  48. GRB000730, Gamma Ray Observations
  49. GRB000812, Radio observations
  50. GRB000801, Gamma Ray Observations
  51. GRB000801, VLT-Antu R-band observations
  52. GRB 991208 Host Galaxy Imaging
  53. IPN localization of GRB000730B
  54. GRB 990510: Possible detection of a host galaxy
  55. GRB 990510 Host Galaxy Discovery
  56. IPN localization of GRB000727
  57. GRB 990712: Late time HST/STIS Observations
  58. GRB 991216, HST/STIS observations
  59. GRB000620, Radio Observations
  60. GRB000630, optical observations
  61. GRB000630, Revised BVRI Field Photometry
  62. GRB000630, Optical Observations
  63. GRB000630, optical observations
  64. GRB000630, optical observations
  65. GRB000630, BVRI Field Photometry
  66. GRB000630, optical observations
  67. GRB000630: Optical observations
  68. GRB000630, Radio Observations
  69. possible optical counterpart of GRB 000630
  70. GRB 000620, optical observations
  71. GRB000418, HST/STIS Observations
  72. GRB990123: Late-time HST/STIS observations of the host
  73. GRB000620, optical observations
  74. GRB000615: H-band observations
  75. GRB990308, HST/STIS observations of the host galaxy
  76. GRB000620 - Optical observations
  77. GRB000620 Optical observations
  78. GRB000620: BeppoSAX WFC and GRBM detection
  79. GRB000607, optical observations
  80. GRB 000615: NIR further observations
  81. GRB990123, HST/STIS observations of the host galaxy
  82. GRB000616 optical observations
  83. GRB 000615, near-infrared observations
  84. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  85. GRB000615, further R-band photometry
  86. GRB 000615: NIR observations
  87. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  88. GRB000615, R-band photometry
  89. The Hosts of GRB 980703 and GRB 971214
  90. GRB 000301C: Further Late-Time HST/STIS observations
  91. GRB000528: follow-up X-ray measurements and update of IPN annulus
  92. GRB980519, HST/STIS observations of the host galaxy
  93. GRB000604 optical non-detection
  94. GRB000604 - Optical observations
  95. GRB000604, optical observations
  96. GRB000528, optical observations at ESO
  97. GRB 000604 optical observations
  98. GRB 000418: Detection of the Host Galaxy
  99. GRB000604, optical observations, comparison with DPOSS
  100. GRB000528, Radio 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