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"

41630 results found.

  1. ASM Localization of GRB 001025
  2. GRB001007, Radio observations
  3. GRB001019, Optical Observations
  4. GRB 001018, Possible Radio Afterglow
  5. GRB001018, Gamma Ray Observations
  6. V,R,I band observations of GRB000926
  7. The Likely Optical/Infrared Afterglow of GRB 001011
  8. HETE positions added to GCN
  9. GRB 001007, BVR-band observations
  10. GRB000926 - Amateur Optical Observations
  11. GRB001007: Optical observations
  12. GRB 000926 : the host galaxy
  13. HETE-2 Launches Successfully
  14. GRB 000926 Chandra Observation
  15. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  16. GRB000926 - Optical observations
  17. GRB000926 - Optical observations
  18. GRB 000926, Optical Decay
  19. GRB000926 - Optical observations
  20. GRB000926 - Optical observations
  21. GRB 000926: optical observations
  22. GRB 000926, Optical Observations
  23. GRB000926 - Optical observations
  24. GRB000911: optical VLT observations
  25. GRB000926 K'-band Observation
  26. GRB000926 optical observations
  27. GRB000926 - Optical observations
  28. J and K band observations of GRB 000926
  29. GRB000911 Optical Observations
  30. GRB 000926: Lightcurve Update and Predictions
  31. GRB 000926, optical observation by Oksanen (vsnet-grb)
  32. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  33. GRB000926: Optical observations
  34. GRB 000926 HST/Chandra TOO Status
  35. Spectroscopic Redshift of GRB 000926
  36. GRB000926, radio observations
  37. GRB 000926: Optical candidate
  38. Optical candidate for 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, BVRI field photometry
  51. GRB000830: Optical observations
  52. GRB000210, Optical observations
  53. Chandra Position of GRB000210
  54. "Snapshot" afterglow IDs and GRB 000830
  55. GRB000830: Optical observations
  56. IPN triangulation of GRB000830
  57. HST/STIS observations of the host galaxy of GRB 980329
  58. HST/STIS observations of the chaotic environment of GRB 980613
  59. SGR 1806-20 burst activity
  60. GRB000812, TNG R-band observations
  61. GRB000801 & GRB000730, Gamma Ray Observations
  62. GRB000730, Gamma Ray Observations
  63. GRB000812, Radio observations
  64. GRB000801, Gamma Ray Observations
  65. GRB000801, VLT-Antu R-band observations
  66. GRB000301C, UBVI optical observations
  67. GRB000801, Radio Observations
  68. GRB 991208 Host Galaxy Imaging
  69. GRB 990510: Possible detection of a host galaxy
  70. GRB 990510 Host Galaxy Discovery
  71. GRB 000727, optical observations
  72. GRB 990705, HST/STIS observations of the host galaxy
  73. GRB 990712: Late time HST/STIS Observations
  74. GRB 991216, HST/STIS observations
  75. GRB000620, Radio Observations
  76. GRB981226, HST/STIS observations of the host galaxy
  77. GRB000630, optical observations
  78. GRB 000630: Detection of the Optical Afterglow
  79. GRB000630, Revised BVRI Field Photometry
  80. GRB000630, Optical Observations
  81. GRB000630, optical observations
  82. GRB000630, optical observations
  83. GRB000630, BVRI Field Photometry
  84. GRB000630, optical observations
  85. GRB000630, optical observations
  86. GRB000630: Optical observations
  87. GRB000630, Radio Observations
  88. possible optical counterpart of GRB 000630
  89. GRB 000623, optical observations
  90. GRB 000620, optical observations
  91. GRB000418, HST/STIS Observations
  92. GRB990123: Late-time HST/STIS observations of the host
  93. GRB 990506, HST/STIS Observations of the Host Galaxy
  94. GRB 000620: J-band observations
  95. GRB000620, optical observations
  96. GRB000615: H-band observations
  97. GRB990308, HST/STIS observations of the host galaxy
  98. GRB000620 - Optical observations
  99. GRB000620 Optical observations
  100. IPN annulus for GRB000620

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