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"

45433 results found.

  1. GRB000210: BeppoSAX GRBM and WFC Detection
  2. Optical observations of GRB000131
  3. GRB000201 Optical Observations
  4. GRB 000201: TAROT optical observations
  5. GRB 000131 Optical Observations
  6. GRB000126 Optical Observations
  7. GRB 991208, radio observations
  8. BATSE+IPN location of GRB000131
  9. IPN localization of GRB000131
  10. GRB 000126, optical observations
  11. GRB000126, optical observations
  12. BATSE location of GRB000126
  13. IPN localization of GRB000126
  14. GRB 000115 Optical observations
  15. BATSE Observations of GRB000115
  16. Correction to GCN 520 (IPN annulus for GRB000115)
  17. Second RXTE Observation of GRB 000115
  18. GRB991216, UBVRIJHK field photometry
  19. GRB991216 late optical observation
  20. Single IPN error box for GRB991229
  21. GCN resumes full operations
  22. GRB 991216 VLBA Observations
  23. BEPPOSAX GRBM Localization of GRB991226
  24. IPN error boxes for GRB991229
  25. GRB 991216: J band spectrophotometry
  26. GRB 991216: Detection of the Host and/or Absorber Galaxy
  27. IPN localization of GRB991226
  28. Single IPN error box for GRB991221
  29. IPN error boxes for GRB991221
  30. GRB 991216 RXTE ASM Observations
  31. IPN error box for GRB991216
  32. GRB 991216: Updated BATSE parameters
  33. Lowell/Perkins observation of GRB 991216
  34. GRB 991217 (SAX J2303.2+0015) Optical observations
  35. GRB991217/SAX J2303.2+0015, optical observations
  36. Chandra observation of the X-ray afterglow of GRB991216
  37. GRB 991216, optical observations
  38. GRB 991216 Optical Observations
  39. GRB 991216 Optical spectroscopy/imaging
  40. VLT spectra of GRB991216
  41. GRB991216 Optical and IR observations
  42. K observations of GRB991216
  43. SAX J2303.2+0015 Optical observations
  44. IR observations of GRB991216
  45. GRB991216 radio observations
  46. GRB991216 radio observations
  47. GRB991216 Spectroscopy
  48. Lowell/Perkins observation of GRB 991216
  49. GRB991216, optical observations
  50. GRB991216 Optical and infrared observations of Beethoven Burst
  51. Refined IPN localization of GRB991216
  52. GRB 991216 Radio Observations
  53. GRB 991217
  54. GRB 991208 Keck Spectroscopy
  55. GRB 991208 Infrared Detection
  56. GRB991216
  57. GRB 991216--Summary of RXTE Observations
  58. GRB 991216 Optical Observations
  59. GRB 991216, optical observations
  60. GRB 991208 SAO-RAS Spectroscopy
  61. SAX J2303.2+0015: an x-ray/GRB?
  62. GRB 991216, Optical Transient
  63. GRB 991216, Optical Afterglow
  64. GRB991216 ('Beethoven Burst') B, R, and K Observations
  65. GRB 991216: Comparison with DPOSS images
  66. GRB991216, infrared observations
  67. GRB991216 Optical Observations
  68. GRB 991208 optical observations
  69. Lowell/Perkins observation of GRB 991216
  70. GRB 991216 Optical Observation
  71. GRB 991208 Keck Spectroscopy
  72. GRB 991216: Extremely bright BATSE burst
  73. R-band Observations of GRB991208 at TNG
  74. GRB991208, optical observations
  75. GRB 991208 Keck Spectroscopy
  76. GRB991208 - millimeter detection
  77. GRB 991208, Optical Observation
  78. GRB991208 15-GHz observations
  79. GRB991208, optical observations
  80. GRB 991208 - OVRO detection
  81. GRB 991208 Optical Decay
  82. GRB 991208 optical observations
  83. GRB 991208 optical observations
  84. GRB 991208: Radio Observations
  85. IPN localization of GRB991208
  86. Optical Observations of GRB991105
  87. GRB991106: BeppoSAX/BATSE results
  88. GRB 991106, optical observations
  89. GRB991106, near-infrared observations
  90. BeppoSAX NFI Observation of GRB991106
  91. GRB 991106, radio observations
  92. GRB991106: the first BeppoSAX short GRB detection?
  93. GRB 991105: BATSE Observations
  94. IPN localization of GRB991105
  95. GRB 991106 Optical Observations
  96. GRB 991105, optical observations
  97. GRB991106, optical observation at SAO-RAS
  98. GRB 991106, LOTIS Optical Observations
  99. GRB 991106, optical observations
  100. BeppoSAX refined position for GRB991106

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