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"

32509 results found.

  1. The Likely Optical/Infrared Afterglow of GRB 001011
  2. HETE positions added to GCN
  3. GRB 001007, BVR-band observations
  4. GRB001007: Optical observations
  5. CONCAM null result on GRB001005
  6. GRB 000926 : the host galaxy
  7. GRB 000926 Chandra Observation
  8. Public availability of BeppoSAX data of GRB000926
  9. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  10. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  11. GRB000926 - Optical observations
  12. GRB000926 - Optical observations
  13. GRB 000926, Optical Decay
  14. GRB000911: VLT infrared observation
  15. GRB000926 - Optical observations
  16. GRB000926 - Optical observations
  17. GRB 000926: optical observations
  18. GRB 000926, Optical Observations
  19. GRB000926 - Optical observations
  20. GRB000911: optical VLT observations
  21. GRB000926 : increasing optical decay slope
  22. GRB000926 optical observations
  23. GRB000926 - Optical observations
  24. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  25. J and K band observations of GRB 000926
  26. GRB000911 Optical Observations
  27. GRB 000926: Lightcurve Update and Predictions
  28. GRB 000926, optical observation by Oksanen (vsnet-grb)
  29. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  30. GRB000926: Optical observations
  31. GRB 000926: Preliminary R-band Lightcurve
  32. GRB 000926 HST/Chandra TOO Status
  33. Spectroscopic Redshift of GRB 000926
  34. GRB 000926, Optical Observation
  35. GRB000926, radio observations
  36. GRB 000926: Optical candidate
  37. Optical candidate for GRB000926
  38. IPN triangulation of GRB000926
  39. GRB 000911, BVRI field photometry
  40. GRB000911: Corrected coordinates
  41. GRB000911: Sub-millimeter observations
  42. GRB000911: Optical Transient
  43. GRB000911, Radio and Optical observations
  44. GRB000911, Radio observations
  45. GRB000911: Optical observations
  46. False GRB alarm from RXTE/ASM on 8 Sept 2000
  47. GRB 000830: Optical observations
  48. GRB000830: Optical observations
  49. GRB000830, TNG B-band observations
  50. GRB000830: Optical observations
  51. GRB000210, Optical observations
  52. Chandra Position of GRB000210
  53. GRB000830: Optical observations
  54. HST/STIS observations of the host galaxy of GRB 980329
  55. HST/STIS observations of the chaotic environment of GRB 980613
  56. GRB000812, TNG R-band observations
  57. GRB000801 & GRB000730, Gamma Ray Observations
  58. GRB000812, Radio observations
  59. GRB000801, VLT-Antu R-band observations
  60. GRB000301C, UBVI optical observations
  61. GRB000801, Radio Observations
  62. GRB 991208 Host Galaxy Imaging
  63. Updated IPN coordinates for GRB000801
  64. IPN localization of GRB000801
  65. IPN localization of GRB000730B
  66. GRB 990510: Possible detection of a host galaxy
  67. GRB 990510 Host Galaxy Discovery
  68. GRB 000727, optical observations
  69. GRB 990705, HST/STIS observations of the host galaxy
  70. GRB 990712: Late time HST/STIS Observations
  71. GRB 991216, HST/STIS observations
  72. GRB000620, Radio Observations
  73. GRB981226, HST/STIS observations of the host galaxy
  74. GRB000630, optical observations
  75. GRB 000630: Detection of the Optical Afterglow
  76. GRB000630, Revised BVRI Field Photometry
  77. GRB000630, Optical Observations
  78. GRB000630, optical observations
  79. GRB000630, optical observations
  80. GRB000630, optical observations
  81. GRB000630, optical observations
  82. GRB000630: Optical observations
  83. GRB000630, Radio Observations
  84. possible optical counterpart of GRB 000630
  85. GRB 000623, optical observations
  86. GRB 000620, optical observations
  87. GRB000418, HST/STIS Observations
  88. GRB990123: Late-time HST/STIS observations of the host
  89. GRB 990506, HST/STIS Observations of the Host Galaxy
  90. GRB 000620: J-band observations
  91. GRB000620, optical observations
  92. GRB000615: H-band observations
  93. GRB990308, HST/STIS observations of the host galaxy
  94. GRB000620 - Optical observations
  95. GRB000620 Optical observations
  96. IPN annulus for GRB000620
  97. GRB000615, Radio observations
  98. GRB000607, optical observations
  99. GRB 000615: NIR further observations
  100. GRB990123, HST/STIS observations of the host galaxy

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