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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"

31741 results found.

  1. GRB 991216, Optical Afterglow
  2. GRB991216 ('Beethoven Burst') B, R, and K Observations
  3. GRB 991216: Comparison with DPOSS images
  4. GRB 991208 optical observations
  5. Lowell/Perkins observation of GRB 991216
  6. GRB 991216 Optical Observation
  7. GRB 991208 Keck Spectroscopy
  8. R-band Observations of GRB991208 at TNG
  9. GRB991208, optical observations
  10. GRB 991208 Keck Spectroscopy
  11. GRB991208 - millimeter detection
  12. GRB 991208, Optical Observation
  13. GRB991208 15-GHz observations
  14. GRB991208, optical observations
  15. GRB 991208 - OVRO detection
  16. GRB 991208 Optical Decay
  17. GRB 991208 optical observations
  18. GRB 991208 optical observations
  19. GRB 991208: Radio Observations
  20. Optical Observations of GRB991105
  21. GRB991106: BeppoSAX/BATSE results
  22. GRB 991106, optical observations
  23. GRB991106, near-infrared observations
  24. BeppoSAX NFI Observation of GRB991106
  25. GRB 991106, radio observations
  26. GRB 991105: BATSE Observations
  27. IPN localization of GRB991105
  28. GRB 991106 Optical Observations
  29. GRB 991105, optical observations
  30. GRB991106, optical observation at SAO-RAS
  31. GRB 991106, LOTIS Optical Observations
  32. GRB 991106, optical observations
  33. Revised BeppoSAX WFC position of GRB991105
  34. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  35. GRB 991014, Optical Observations
  36. GRB 991014 - BeppoSAX NFI observations
  37. GRB 991014, Optical Observations
  38. GRB 991014, Optical Observations
  39. GRB 991014, optical observations
  40. Super-LOTIS optical observation of GRB991014
  41. IPN/NFI error box for GRB991014
  42. IPN localization of GRB991014 - CORRECTION
  43. IPN localization of GRB991014
  44. GRB 990915 optical observations
  45. GRB 990907 optical observations
  46. Optical Observations of GRB990907
  47. IPN error box for GRB990915 (=BATSE 7766)
  48. IPN localization of BATSE #7766 (GRB990915)
  49. GRB990907: BeppoSAX follow up and X-ray afterglow
  50. GRB990907 and 990908
  51. IPN localization of GRB990907
  52. GRB 990712 Late Optical Decay and Host Galaxy
  53. GRB 990712, Optical Observation
  54. GRB990806 BeppoSAX follow up
  55. GRB990806: BATSE Observations
  56. GRB 990806 Optical observations
  57. Optical Observations of GRB990806
  58. GRB 990806, Optical Observations
  59. GRB 990806, optical observations
  60. GRB 990806, Optical Observations
  61. GRB990806 UBVRIJHK observations
  62. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  63. VLT spectrum of GRB990712
  64. GRB 990712
  65. Late-time HST/STIS Observations of GRB 990510
  66. BeppoSAX NFI Observation of GRB990705
  67. BeppoSAX NFI Observation of GRB990705
  68. Updated Astrometry for the IR Counterpart of GRB990705
  69. GRB 990705, R-band observations
  70. Updated IPN localization of GRB990705
  71. IPN localization of GRB990704
  72. IPN localization of GRB990705
  73. Infrared and Optical Observations of GRB990705
  74. GRB 990705, radio observations
  75. GRB990704: SAX-NFI results summary
  76. GRB990704 radio and optical observations
  77. GRB 990704 X-ray Observations
  78. GRB 990704 Optical Observations
  79. GRB 990704, optical observations
  80. GRB990704
  81. GRB990704
  82. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  83. GRB990704, optical observations
  84. GRB990704: possible X-ray afterglow
  85. Identification of a possible optical counterpart for GRB990704
  86. GRB990704
  87. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  88. Optical Observations of GRB990627
  89. GRB 990627, radio observations
  90. GRB990627: BeppoSAX-WFC final location
  91. GRB 990506 - clarification to GCN 352
  92. GRB 990506 - Optical Observations
  93. Optical Observations of GRB 990506
  94. GRB 990506 Radio Transient
  95. GRB990527 Optical Observations
  96. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  97. Late Afterglows of GRBs 990510, 990123
  98. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  99. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  100. X-ray/GRB 1SAX J0835.9+5118, Optical Observations

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