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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"

31633 results found.

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

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