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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.

Lucene Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"
  1. GRB991216, infrared observations
  2. GRB991216 Optical Observations
  3. GRB 991208 optical observations
  4. Lowell/Perkins observation of GRB 991216
  5. GRB 991216 Optical Observation
  6. GRB 991208 Keck Spectroscopy
  7. GRB 991216: Extremely bright BATSE burst
  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. IPN localization of GRB991208
  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. GRB991106: the first BeppoSAX short GRB detection?
  28. GRB 991105: BATSE Observations
  29. IPN localization of GRB991105
  30. GRB 991106 Optical Observations
  31. GRB 991105, optical observations
  32. GRB991106, optical observation at SAO-RAS
  33. GRB 991106, LOTIS Optical Observations
  34. GRB 991106, optical observations
  35. BeppoSAX refined position for GRB991106
  36. BeppoSAX GRB Alert: GRB991106
  37. Revised BeppoSAX WFC position of GRB991105
  38. GRB991105: SAX-GRBM/-WFC detection
  39. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  40. GRB ALERT: GRB991105
  41. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  42. GRB 991014, Optical Observations
  43. GRB 991014 - BeppoSAX NFI observations
  44. GRB 991014, Optical Observations
  45. GRB 991014, radio observations
  46. GRB991014 BATSE Observations
  47. GRB 991014, Optical Observations
  48. GRB 991014, optical observations
  49. Super-LOTIS optical observation of GRB991014
  50. IPN/NFI error box for GRB991014
  51. IPN localization of GRB991014 - CORRECTION
  52. IPN localization of GRB991014
  53. BeppoSAX ALERT: GRB991014
  54. GRB 990915 optical observations
  55. GRB 990907 optical observations
  56. BATSE GRB trigger criteria
  57. Optical Observations of GRB990907
  58. IPN error box for GRB990915 (=BATSE 7766)
  59. IPN localization of BATSE #7766 (GRB990915)
  60. GRB990907: BeppoSAX follow up and X-ray afterglow
  61. GRB990907 and 990908
  62. IPN localization of GRB990907
  63. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  64. GRB990907: refined WFC position
  65. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  66. GRB 990712 Late Optical Decay and Host Galaxy
  67. GRB 990712, Optical Observation
  68. GRB990806 BeppoSAX follow up
  69. GRB990806: BATSE Observations
  70. GRB 990806 Optical observations
  71. Optical Observations of GRB990806
  72. GRB 990806, Optical Observations
  73. GRB 990806, optical observations
  74. GRB 990806, Optical Observations
  75. GRB990806 UBVRIJHK observations
  76. GRB990806: possible X-ray afterglow, BeppoSAX
  77. BeppoSAX ALERT GRB990806: Summer GRB
  78. GRB 990712 Optical Observations
  79. GRB990705: No Evidence for Neutrino Signal
  80. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  81. VLT spectrum of GRB990712
  82. GRB 990712
  83. Late-time HST/STIS Observations of GRB 990510
  84. Refined BeppoSAX-WFC position of GRB990712
  85. BeppoSAX NFI Observation of GRB990705
  86. BeppoSAX NFI Observation of GRB990705
  87. Updated Astrometry for the IR Counterpart of GRB990705
  88. GRB 990705, R-band observations
  89. Updated IPN localization of GRB990705
  90. IPN localization of GRB990704
  91. IPN localization of GRB990705
  92. Infrared and Optical Observations of GRB990705
  93. GRB 990705, radio observations
  94. GRB990704: SAX-NFI results summary
  95. GRB990704 radio and optical observations
  96. BeppoSAX GRB990705: possible X-ray afterglow
  97. GRB 990704 X-ray Observations
  98. GRB 990704 Optical Observations
  99. GRB 990704, optical observations
  100. GRB990704

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