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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"

31742 results found.

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

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