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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"

31737 results found.

  1. Lowell/Perkins observation of GRB 991216
  2. GRB 991216 Optical Observation
  3. GRB 991208 Keck Spectroscopy
  4. R-band Observations of GRB991208 at TNG
  5. GRB991208, optical observations
  6. GRB 991208 Keck Spectroscopy
  7. GRB991208 - millimeter detection
  8. GRB 991208, Optical Observation
  9. GRB991208 15-GHz observations
  10. GRB991208, optical observations
  11. GRB 991208 - OVRO detection
  12. GRB 991208 Optical Decay
  13. GRB 991208 optical observations
  14. GRB 991208 optical observations
  15. GRB 991208: Radio Observations
  16. Optical Observations of GRB991105
  17. GRB991106: BeppoSAX/BATSE results
  18. GRB 991106, optical observations
  19. GRB991106, near-infrared observations
  20. BeppoSAX NFI Observation of GRB991106
  21. GRB 991106, radio observations
  22. GRB 991105: BATSE Observations
  23. IPN localization of GRB991105
  24. GRB 991106 Optical Observations
  25. GRB 991105, optical observations
  26. GRB991106, optical observation at SAO-RAS
  27. GRB 991106, LOTIS Optical Observations
  28. GRB 991106, optical observations
  29. Revised BeppoSAX WFC position of GRB991105
  30. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  31. GRB 991014, Optical Observations
  32. GRB 991014 - BeppoSAX NFI observations
  33. GRB 991014, Optical Observations
  34. GRB 991014, Optical Observations
  35. GRB 991014, optical observations
  36. Super-LOTIS optical observation of GRB991014
  37. IPN/NFI error box for GRB991014
  38. IPN localization of GRB991014 - CORRECTION
  39. IPN localization of GRB991014
  40. GRB 990915 optical observations
  41. GRB 990907 optical observations
  42. Optical Observations of GRB990907
  43. IPN error box for GRB990915 (=BATSE 7766)
  44. IPN localization of BATSE #7766 (GRB990915)
  45. GRB990907: BeppoSAX follow up and X-ray afterglow
  46. GRB990907 and 990908
  47. IPN localization of GRB990907
  48. GRB 990712 Late Optical Decay and Host Galaxy
  49. GRB 990712, Optical Observation
  50. GRB990806 BeppoSAX follow up
  51. GRB990806: BATSE Observations
  52. GRB 990806 Optical observations
  53. Optical Observations of GRB990806
  54. GRB 990806, Optical Observations
  55. GRB 990806, optical observations
  56. GRB 990806, Optical Observations
  57. GRB990806 UBVRIJHK observations
  58. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  59. VLT spectrum of GRB990712
  60. GRB 990712
  61. Late-time HST/STIS Observations of GRB 990510
  62. BeppoSAX NFI Observation of GRB990705
  63. BeppoSAX NFI Observation of GRB990705
  64. Updated Astrometry for the IR Counterpart of GRB990705
  65. GRB 990705, R-band observations
  66. Updated IPN localization of GRB990705
  67. IPN localization of GRB990704
  68. IPN localization of GRB990705
  69. Infrared and Optical Observations of GRB990705
  70. GRB 990705, radio observations
  71. GRB990704: SAX-NFI results summary
  72. GRB990704 radio and optical observations
  73. GRB 990704 X-ray Observations
  74. GRB 990704 Optical Observations
  75. GRB 990704, optical observations
  76. GRB990704
  77. GRB990704
  78. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  79. GRB990704, optical observations
  80. GRB990704: possible X-ray afterglow
  81. Identification of a possible optical counterpart for GRB990704
  82. GRB990704
  83. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  84. Optical Observations of GRB990627
  85. GRB 990627, radio observations
  86. GRB990627: BeppoSAX-WFC final location
  87. GRB 990506 - clarification to GCN 352
  88. GRB 990506 - Optical Observations
  89. Optical Observations of GRB 990506
  90. GRB 990506 Radio Transient
  91. GRB990527 Optical Observations
  92. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  93. Late Afterglows of GRBs 990510, 990123
  94. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  95. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  96. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  97. GRB 990506 optical observation
  98. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  99. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  100. X-ray/GRB 1SAX J0835.9+5118, Optical Observation

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