An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

   Homepage   
   


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Number of Results: 1 Search : companion of Sirius
companion of Sirius
  همدم ِ تیشتر   
hamdam-e Tištar

Fr.: compagnon de Sirius   

A faint star of 8th magnitude in a binary system with → Sirius. Called also Sirius B, it is a → white dwarf with a mass comparable to that of the Sun, but with a diameter smaller than that of the Earth. The mean distance between the stars is about 20 A.U. (angular separation 4.6 seconds of arc), and their period of revolution about 50 years. This star was discovered in 1844 by Friedrich Bessel, who noticed that Sirius had a slight wobbling motion, as if it was orbiting an unseen object. In 1863, the optician and telescope maker Alvan Clark spotted the companion. The star was later determined to be a → white dwarf.

companion; → Sirius.