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"

24847 results found.

  1. XMM-Newton observation of GRB001025
  2. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  3. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  4. GRB001007: Optical observations
  5. ASM Localization of GRB 001025
  6. GRB001007, Radio observations
  7. GRB 001018, Possible Radio Afterglow
  8. GRB001018, Gamma Ray Observations
  9. IPN TRIANGULATION OF GRB001019
  10. IPN TRIANGULATION OF GRB001018
  11. IPN TRIANGULATION OF GRB 001017
  12. V,R,I band observations of GRB000926
  13. HETE positions added to GCN
  14. GRB000926 - Amateur Optical Observations
  15. CONCAM null result on GRB001005
  16. IPN triangulation of GRB001005
  17. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  18. GRB000926 - Optical observations
  19. GRB000926 - Optical observations
  20. GRB 000926, Optical Decay
  21. GRB000911: VLT infrared observation
  22. GRB 000926, Optical Observations
  23. GRB000926 K'-band Observation
  24. J and K band observations of GRB 000926
  25. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  26. CONCAM crude optical limits before and after GRB000926
  27. GRB 000926: Preliminary R-band Lightcurve
  28. Spectroscopic Redshift of GRB 000926
  29. GRB 000926: Optical candidate
  30. Optical candidate for GRB000926
  31. GRB 000911, BVRI field photometry
  32. GRB000911, Radio and Optical observations
  33. GRB000911: Optical observations
  34. GRB000830, BVRI field photometry
  35. GRB000210, Optical observations
  36. "Snapshot" afterglow IDs and GRB 000830
  37. GRB000730, Gamma Ray Observations
  38. GRB000812, Radio observations
  39. GRB000801, Gamma Ray Observations
  40. GRB000801, VLT-Antu R-band observations
  41. GRB 991208 Host Galaxy Imaging
  42. IPN localization of GRB000730B
  43. GRB 990510: Possible detection of a host galaxy
  44. GRB 990510 Host Galaxy Discovery
  45. IPN localization of GRB000727
  46. GRB 990712: Late time HST/STIS Observations
  47. GRB 991216, HST/STIS observations
  48. GRB000620, Radio Observations
  49. GRB000630, optical observations
  50. GRB000630, Revised BVRI Field Photometry
  51. GRB000630, Optical Observations
  52. GRB000630, optical observations
  53. GRB000630, optical observations
  54. GRB000630, BVRI Field Photometry
  55. GRB000630, optical observations
  56. GRB000630: Optical observations
  57. GRB000630, Radio Observations
  58. possible optical counterpart of GRB 000630
  59. GRB 000620, optical observations
  60. GRB000418, HST/STIS Observations
  61. GRB990123: Late-time HST/STIS observations of the host
  62. GRB000620, optical observations
  63. GRB000615: H-band observations
  64. GRB990308, HST/STIS observations of the host galaxy
  65. GRB000620 - Optical observations
  66. GRB000620 Optical observations
  67. GRB000620: BeppoSAX WFC and GRBM detection
  68. GRB000607, optical observations
  69. GRB 000615: NIR further observations
  70. GRB990123, HST/STIS observations of the host galaxy
  71. GRB000616 optical observations
  72. GRB 000615, near-infrared observations
  73. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  74. GRB000615, further R-band photometry
  75. GRB 000615: NIR observations
  76. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  77. GRB000615, R-band photometry
  78. The Hosts of GRB 980703 and GRB 971214
  79. GRB 000301C: Further Late-Time HST/STIS observations
  80. GRB000528: follow-up X-ray measurements and update of IPN annulus
  81. GRB980519, HST/STIS observations of the host galaxy
  82. GRB000604 optical non-detection
  83. GRB000604 - Optical observations
  84. GRB000604, optical observations
  85. GRB000528, optical observations at ESO
  86. GRB 000604 optical observations
  87. GRB 000418: Detection of the Host Galaxy
  88. GRB000604, optical observations, comparison with DPOSS
  89. GRB000528, Radio Observations
  90. X-ray Afterglow of GRB 000529
  91. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  92. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  93. GRB 000528 - WFC measurements
  94. GRB000519, BVRI field photometry
  95. IPN triangulation of GRB000519
  96. GRB000508B, optical photometry
  97. GRB000508B, BVR field photometry
  98. Possible GRB-related phenomenon
  99. RXTE/ASM and IPN localization of GRB 000508B
  100. GRB000424, UBVRI field photometry

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