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"

26301 results found.

  1. Lowell/Perkins observation of GRB 991216
  2. GRB 991208 Keck Spectroscopy
  3. GRB 991216: Extremely bright BATSE burst
  4. R-band Observations of GRB991208 at TNG
  5. GRB991208, optical observations
  6. GRB 991208 Keck Spectroscopy
  7. GRB991208 - millimeter detection
  8. GRB991208 15-GHz observations
  9. GRB991208, optical observations
  10. GRB 991208 Optical Decay
  11. GRB 991208 optical observations
  12. GRB 991208 optical observations
  13. IPN localization of GRB991208
  14. Optical Observations of GRB991105
  15. GRB991106: BeppoSAX/BATSE results
  16. GRB 991106, optical observations
  17. GRB991106, near-infrared observations
  18. BeppoSAX NFI Observation of GRB991106
  19. GRB 991105: BATSE Observations
  20. IPN localization of GRB991105
  21. GRB 991106 Optical Observations
  22. GRB 991105, optical observations
  23. GRB 991106, optical observations
  24. BeppoSAX GRB Alert: GRB991106
  25. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  26. GRB ALERT: GRB991105
  27. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  28. GRB 991014, radio observations
  29. GRB991014 BATSE Observations
  30. GRB 991014, optical observations
  31. IPN/NFI error box for GRB991014
  32. BeppoSAX ALERT: GRB991014
  33. GRB 990915 optical observations
  34. GRB 990907 optical observations
  35. GRB990907 and 990908
  36. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  37. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  38. GRB 990712 Late Optical Decay and Host Galaxy
  39. GRB 990712, Optical Observation
  40. GRB990806 BeppoSAX follow up
  41. GRB990806: BATSE Observations
  42. Optical Observations of GRB990806
  43. GRB 990806, Optical Observations
  44. BeppoSAX ALERT GRB990806: Summer GRB
  45. GRB 990712 Optical Observations
  46. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  47. Late-time HST/STIS Observations of GRB 990510
  48. Refined BeppoSAX-WFC position of GRB990712
  49. BeppoSAX NFI Observation of GRB990705
  50. BeppoSAX NFI Observation of GRB990705
  51. GRB 990705, radio observations
  52. GRB 990704, optical observations
  53. GRB990704
  54. GRB990704, optical observations
  55. Refined BeppoSAX-WFC position of GRB990704
  56. GRB990704: BeppoSAX detection
  57. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  58. Optical Observations of GRB990627
  59. GRB 990627, radio observations
  60. GRB990627: BeppoSAX-WFC final location
  61. BeppoSAX: GRB990625
  62. Late-time HST/STIS Observation of GRB 990123
  63. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  64. Late Afterglows of GRBs 990510, 990123
  65. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  66. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  67. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  68. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  69. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  70. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  71. radio observations of X-ray/GRB transient field
  72. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  73. Optical report on X-ray/GRB transient
  74. radio detection of X-ray/GRB transient
  75. BeppoSAX: A new fast X-ray transient
  76. GRB990510: photometric and spectroscopic observations with the VLT
  77. GRB 990510: optical observations
  78. GRB 990506 R band observations
  79. VLT spectrum of GRB990510
  80. GRB 990510: Broad Band Break
  81. GRB 990510: BATSE Observations
  82. GRB 990510 Optical Observations
  83. GRB 990510, BVI photometry
  84. GRB 990510 optical observations
  85. GRB 990510: BeppoSAX/GRBM observations
  86. GRB990510 optical observations
  87. GRB 990510 optical observations
  88. GRB 990510 optical observations
  89. GRB 990506: BATSE Observations
  90. GRB 990506, optical observations
  91. GRB 990510: Final BeppoSAX-WFC Coordinates
  92. GRB 990506, Optical Observations
  93. GRB 990506 optical observations
  94. GRB 990506 optical observations
  95. GRB990506 observation plan
  96. Refined IPN error box for GRB990506
  97. GRB 990506: Limits on the possible optical transient
  98. GRB 990506, optical observations from +1 to +3 hours
  99. IPN localization for GRB990506
  100. GRB 970228: Redshift and properties of the host galaxy

Advanced

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