Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

42597 results found.

  1. CONCAM null result on GRB001005
  2. IPN triangulation of GRB001007
  3. GRB 000926 : the host galaxy
  4. HETE-2 Launches Successfully
  5. IPN triangulation of GRB001005
  6. HETE-2 48 hour Launch Delay
  7. GRB 000926 Chandra Observation
  8. IPN triangulation of GRB 001004
  9. Public availability of BeppoSAX data of GRB000926
  10. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  11. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  12. GRB000926 - Optical observations
  13. GRB000926 - Optical observations
  14. GRB 000926, Optical Decay
  15. GRB000911: VLT infrared observation
  16. GRB000926 - Optical observations
  17. GRB000926 - Optical observations
  18. GRB 000926: optical observations
  19. GRB000926 - Optical observations
  20. GRB000911: optical VLT observations
  21. GRB000926 K'-band Observation
  22. GRB000926 : increasing optical decay slope
  23. GRB000926 optical observations
  24. GRB000926 - Optical observations
  25. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  26. J and K band observations of GRB 000926
  27. GRB000911 Optical Observations
  28. GRB 000926: Lightcurve Update and Predictions
  29. GRB 000926, optical observation by Oksanen (vsnet-grb)
  30. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  31. GRB000926: Optical observations
  32. CONCAM crude optical limits before and after GRB000926
  33. GRB 000926: Preliminary R-band Lightcurve
  34. GRB 000926 HST/Chandra TOO Status
  35. Spectroscopic Redshift of GRB 000926
  36. GRB 000926, Optical Observation
  37. GRB000926, radio observations
  38. GRB 000926: Optical candidate
  39. Optical candidate for GRB000926
  40. IPN triangulation of GRB000926
  41. IPN triangulation of GRB000926
  42. GRB 000911, BVRI field photometry
  43. GRB000911: Corrected coordinates
  44. GRB000911: Sub-millimeter observations
  45. IPN triangulation of GRB000925
  46. GRB000911: Optical Transient
  47. GRB000911, Radio and Optical observations
  48. GRB000911, Radio observations
  49. IPN triangulation of GRB000911
  50. IPN triangulation of GRB000910
  51. False GRB alarm from RXTE/ASM on 8 Sept 2000
  52. GRB 000830: Optical observations
  53. GRB000830: Optical observations
  54. GRB000830, TNG B-band observations
  55. GRB000830, BVRI field photometry
  56. GRB000830: Optical observations
  57. GRB000210, Optical observations
  58. "Snapshot" afterglow IDs and GRB 000830
  59. GRB000830: Optical observations
  60. IPN triangulation of GRB000830
  61. HST/STIS observations of the host galaxy of GRB 980329
  62. HST/STIS observations of the chaotic environment of GRB 980613
  63. IPN localization of GRB000820
  64. SGR 1806-20 burst activity
  65. GRB000812, TNG R-band observations
  66. GRB000730, Gamma Ray Observations
  67. GRB000812, Radio observations
  68. IPN localization of GRB000812
  69. IPN localization of GRB000811
  70. GRB000801, Gamma Ray Observations
  71. GRB000801, VLT-Antu R-band observations
  72. GRB000301C, UBVI optical observations
  73. GRB000801, Radio Observations
  74. GRB 991208 Host Galaxy Imaging
  75. IPN localization of GRB000801
  76. IPN localization of GRB000730B
  77. IPN localization of GRB000730B
  78. IPN localization of GRB000730
  79. GRB 990510: Possible detection of a host galaxy
  80. GRB 990510 Host Galaxy Discovery
  81. GRB 000727, optical observations
  82. IPN localization of GRB000727
  83. GRB 990705, HST/STIS observations of the host galaxy
  84. GRB 990712: Late time HST/STIS Observations
  85. GRB 991216, HST/STIS observations
  86. GRB000620, Radio Observations
  87. GRB981226, HST/STIS observations of the host galaxy
  88. GRB000630, optical observations
  89. GRB 000630: Detection of the Optical Afterglow
  90. GRB000630, Revised BVRI Field Photometry
  91. GRB000630, Optical Observations
  92. GRB000630, optical observations
  93. GRB000630, optical observations
  94. GRB000630, BVRI Field Photometry
  95. GRB000630, optical observations
  96. GRB000630, optical observations
  97. GRB000630: Optical observations
  98. GRB000630, Radio Observations
  99. possible optical counterpart of GRB 000630
  100. IPN triangulation of GRB000630

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