Skip to main content
U.S. flag

An official website of the United States government

GCN Circulars are now part of the new GCN! 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. SGR1627-41, BeppoSAX-GRBM detections
  2. SGR 1627-41
  3. GRB 980613 Optical Observations
  4. GRB 980613 optical observations
  5. Discovery of a new SGR source, SGR1627-41
  6. GRB980613 Optical Observations
  7. GRB980613 observations from Palomar
  8. GRB980613 BeppoSAX-NFI follow up
  9. GRB 980613 new optical/IR observations
  10. GRB 980613 optical/IR obs.
  11. GRB980613 Near Infra-Red Observations
  12. GRB980611
  13. GRB980613, BeppoSAX WFC positions
  14. GRB971214 Secondary Standards
  15. SGR 1900+14
  16. GRB980519 Secondary Standards
  17. SGR1900+14
  18. SGR1900+14
  19. BATSE on-board GRB trigger change
  20. GRB 980519 Optical Observations
  21. GRB980519 optical observations
  22. GRB980519 I-band observations
  23. GRB 980519
  24. GRB980519 optical observations
  25. GRB 980519 Optical Observations
  26. GRB980519 BATSE Observations
  27. GRB970519, optical follow-up at Schmidt Calern
  28. GRB980519 optical observations
  29. GRB980519 Optical Observations
  30. GRB980519 Optical Observations
  31. GRB980519 IPN POSITION
  32. GRB980519 Optical Observations
  33. GRB 980519 Optical Observations
  34. GRB980519 optical observations
  35. GRB980515, BeppoSAX IAUC to be submitted
  36. BATSE on-board GRB trigger change
  37. GRB980519, BeppoSAX-WFC updated position
  38. GRB980519, BeppoSAX-WFC position
  39. GRB980515: SAX-WFC updated position
  40. BeppoSAX GRB ALERT: updated position of grb980515
  41. GRB 980425 Radio Light Curve
  42. GRB 980425 Brightness Temperature
  43. BSAX Observations of GRB980425 field
  44. IPN web site of GRBs
  45. GRB980425 BATSE observations
  46. SAX J0840.7+2248 Optical Observations
  47. GRB 980425 optical observations
  48. GRB980425: optical obs.
  49. GRB980425: Radio Observations
  50. GRB 980425 optical observations
  51. report on BSAX observations of GRB980425
  52. GRB 980425 optical observations
  53. GRB 980329 ROSAT observation
  54. GRB980326 X-ray Observations
  55. GRB980326, optical observations
  56. GRB980326, optical observations
  57. GRB980329, Fading IR counterpart to radio source
  58. GRByymmdd, Announcement of automation
  59. GRB980326 IPN annulus
  60. GRB980329
  61. GRB980329 Keck K-band observations
  62. GRB980329 sub-millimeter observations
  63. GRB980329 IPN annulus
  64. GRB980329 optical observations
  65. GRB980329 near-IR observations
  66. GRB980329 near-IR observations
  67. GRB980329 optical observations
  68. GRB980329 infrared observations
  69. GRB980329 optical observations
  70. GRB980326 optical observations
  71. GRB980329 optical observations
  72. GRB980329 VLA observations
  73. GRB980329 near IR observations
  74. GRB980329 optical observations
  75. GRB980329 optical observations
  76. GRB980329 optical observations
  77. GRB980326 optical observations
  78. GRB980326 optical observations
  79. GRB980326 optical observations
  80. GRB980326 optical observations
  81. GRB970508 SAO RAS optical observations
  82. Untitled
  83. Untitled
  84. Untitled
  85. Untitled
  86. Untitled
  87. Untitled
  88. Untitled
  89. Untitled
  90. Untitled
  91. Untitled
  92. Untitled
  93. Untitled
  94. Untitled
  95. Untitled
  96. Untitled
  97. Untitled
  98. Untitled
  99. Untitled
  100. Untitled
Looking for U.S. government information and services? Visit USA.gov