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"

23575 results found.

  1. XMM-Newton observation of GRB001025
  2. GRB001025B, Radio observations
  3. GRB 001025 Optical Observations
  4. GRB 001025A, optical observation
  5. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  6. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  7. IPN triangulation of GRB001025
  8. ASM Localization of GRB 001025
  9. IPN TRIANGULATION OF GRB001020
  10. IPN TRIANGULATION OF GRB001019
  11. CORRECTION TO PEAK FLUX OF GRB001018
  12. IPN TRIANGULATION OF GRB001018
  13. IPN TRIANGULATION OF GRB 001017
  14. GRB 000926: Improved Absorber Redshift
  15. V,R,I band observations of GRB000926
  16. The Likely Optical/Infrared Afterglow of GRB 001011
  17. IPN triangulation of GRB001007
  18. GRB 000926 : the host galaxy
  19. IPN triangulation of GRB001005
  20. HETE-2 48 hour Launch Delay
  21. GRB 000926 Chandra Observation
  22. IPN triangulation of GRB 001004
  23. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  24. GRB000926 - Optical observations
  25. GRB000926 - Optical observations
  26. GRB000926 - Optical observations
  27. GRB000926 - Optical observations
  28. GRB000926 - Optical observations
  29. GRB000926 K'-band Observation
  30. GRB000926 optical observations
  31. GRB000926 - Optical observations
  32. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  33. CONCAM crude optical limits before and after GRB000926
  34. GRB 000926: Preliminary R-band Lightcurve
  35. IPN triangulation of GRB000926
  36. IPN triangulation of GRB000926
  37. GRB 000911, BVRI field photometry
  38. IPN triangulation of GRB000925
  39. IPN triangulation of GRB000911
  40. IPN triangulation of GRB000910
  41. False GRB alarm from RXTE/ASM on 8 Sept 2000
  42. GRB 000830: Optical observations
  43. GRB000830, TNG B-band observations
  44. GRB000830, BVRI field photometry
  45. GRB000210, Optical observations
  46. IPN triangulation of GRB000830
  47. IPN localization of GRB000820
  48. GRB000812, TNG R-band observations
  49. GRB000730, Gamma Ray Observations
  50. GRB000812, Radio observations
  51. IPN localization of GRB000812
  52. IPN localization of GRB000811
  53. GRB000801, Gamma Ray Observations
  54. GRB000801, Radio Observations
  55. GRB 991208 Host Galaxy Imaging
  56. Updated IPN coordinates for GRB000801
  57. IPN localization of GRB000801
  58. IPN localization of GRB000730B
  59. IPN localization of GRB000730B
  60. IPN localization of GRB000730
  61. GRB 000727, optical observations
  62. IPN localization of GRB000727
  63. GRB 990705, HST/STIS observations of the host galaxy
  64. GRB 991216, HST/STIS observations
  65. GRB 000630: Detection of the Optical Afterglow
  66. GRB000630, Revised BVRI Field Photometry
  67. GRB000630, optical observations
  68. GRB000630, BVRI Field Photometry
  69. GRB000630, optical observations
  70. GRB000630, optical observations
  71. GRB000630: Optical observations
  72. IPN triangulation of GRB000630
  73. GRB 000623, optical observations
  74. GRB 000620, optical observations
  75. GRB000418, HST/STIS Observations
  76. GRB000623
  77. GRB 000620: J-band observations
  78. GRB000620, optical observations
  79. GRB000615: H-band observations
  80. GRB000620: BeppoSAX WFC and GRBM detection
  81. GRB000615, Radio observations
  82. GRB000607, optical observations
  83. GRB 000615, near-infrared observations
  84. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  85. GRB000616 [IPN Position]
  86. GRB000615B [IPN Position]
  87. GRB000615, further R-band photometry
  88. GRB000615, R-band photometry
  89. GRB 000301C: Further Late-Time HST/STIS observations
  90. GRB000528: follow-up X-ray measurements and update of IPN annulus
  91. Optical Follow-up of GRB000529 Error Box
  92. GRB000607, Radio Observations
  93. GRB000604 optical non-detection
  94. GRB000604 - Optical observations
  95. GRB000607, A SHORT, HARD BURST
  96. GRB000604, optical observations
  97. GRB 000604 optical observations
  98. GRB 000418: Detection of the Host Galaxy
  99. GRB000604 [IPN Position]
  100. X-ray Afterglow of GRB 000529

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