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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"

32532 results found.

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

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