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

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov