Skip to main content
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. 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. GRB 990712, Optical Observation
  2. GRB990806 BeppoSAX follow up
  3. GRB990806: BATSE Observations
  4. GRB 990806 Optical observations
  5. Optical Observations of GRB990806
  6. GRB 990806, Optical Observations
  7. GRB 990806, optical observations
  8. GRB 990806, Optical Observations
  9. GRB990806 UBVRIJHK observations
  10. GRB990806: possible X-ray afterglow, BeppoSAX
  11. BeppoSAX ALERT GRB990806: Summer GRB
  12. GRB 990712 Optical Observations
  13. GRB990705: No Evidence for Neutrino Signal
  14. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  15. VLT spectrum of GRB990712
  16. GRB 990712
  17. Late-time HST/STIS Observations of GRB 990510
  18. Refined BeppoSAX-WFC position of GRB990712
  19. BeppoSAX NFI Observation of GRB990705
  20. BeppoSAX NFI Observation of GRB990705
  21. Updated Astrometry for the IR Counterpart of GRB990705
  22. GRB 990705, R-band observations
  23. Updated IPN localization of GRB990705
  24. IPN localization of GRB990704
  25. IPN localization of GRB990705
  26. Infrared and Optical Observations of GRB990705
  27. GRB 990705, radio observations
  28. GRB990704: SAX-NFI results summary
  29. GRB990704 radio and optical observations
  30. BeppoSAX GRB990705: possible X-ray afterglow
  31. GRB 990704 X-ray Observations
  32. GRB 990704 Optical Observations
  33. GRB 990704, optical observations
  34. GRB990704
  35. GRB990705: Intriguing Positional Coincidences
  36. GRB990704
  37. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  38. GRB990704, optical observations
  39. GRB990704: possible X-ray afterglow
  40. Identification of a possible optical counterpart for GRB990704
  41. GRB990704
  42. Refined BeppoSAX-WFC position of GRB990704
  43. GRB990704: BeppoSAX detection
  44. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  45. Optical Observations of GRB990627
  46. GRB 990627, radio observations
  47. GRB990627: BeppoSAX-WFC final location
  48. BeppoSAX: GRB990625
  49. Late-time HST/STIS Observation of GRB 990123
  50. GRB 990506 - clarification to GCN 352
  51. GRB 990506 - Optical Observations
  52. Optical Observations of GRB 990506
  53. GRB 990506 Radio Transient
  54. GRB990527 Optical Observations
  55. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  56. IPN error box for GRB990527
  57. Late Afterglows of GRBs 990510, 990123
  58. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  59. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  60. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  61. GRB 990506 optical observation
  62. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  63. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  64. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  65. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  66. radio observations of X-ray/GRB transient field
  67. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  68. Optical report on X-ray/GRB transient
  69. radio detection of X-ray/GRB transient
  70. BeppoSAX: A new fast X-ray transient
  71. GRB 990510: optical observations
  72. GRB990510: photometric and spectroscopic observations with the VLT
  73. GRB 990510: optical linear polarization
  74. GRB 990510: optical observations
  75. GRB990510, VI observations
  76. GRB 990506 R band observations
  77. GRB990510: X-ray afterglow
  78. GRB 990510: optical observation
  79. VLT spectrum of GRB990510
  80. GRB 990510: Broad Band Break
  81. GRB 990510: BATSE Observations
  82. GRB990510: optical observation
  83. GRB 990510 Optical Observations
  84. GRB 990510, BVI photometry
  85. GRB 990510 optical observations
  86. GRB 990510: BeppoSAX/GRBM observations
  87. GRB990510 optical observations
  88. GRB990510
  89. GRB 990510 optical observations
  90. GRB 990510 optical observations
  91. Galactic extinction towards GRB 990510
  92. GRB990510: NFI X-ray source
  93. GRB 990510 optical observations
  94. IPN localization of GRB990510
  95. GRB 990506 Radio Observations
  96. GRB 990123, optical monitoring
  97. GRB 990506: BATSE Observations
  98. GRB 990506, optical observations
  99. GRB 990510: Final BeppoSAX-WFC Coordinates
  100. GRB 990506, Optical Observations

Advanced

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