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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"

31730 results found.

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

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