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HD 13189 is an 8th magnitude star in Triangulum constellation. In 2005, a planetary companion or brown dwarf was announced in orbit around this star. At the time, the parallax estimate was , which would suggest a distance of with a high margin of error.〔 In 2007, van Leeuwen published a revised parallax measurement of , which corresponds to a distance of with a smaller but still significant margin of error.〔 It has a spectral classification of K1II-III, making it a giant star that has evolved away from the main sequence. The mass is 2–7 times the Sun,〔 while measurements of the star's radius give estimates of 45.5〔 or 50.4〔 solar radii. This mass range is typical of a B-type main sequence star,〔 suggesting the star belong to stellar class B when it was on the main sequence. The atmosphere of the star displays short period radial velocity variations with a primary period of 4.89 days. This behavior is typical for giant K-type stars such as this and it is not the result of a close-orbit planetary companion.〔 The star is possibly the most massive of all planet-harboring stars〔(【引用サイトリンク】 work=The Extrasolar Planets Encyclopaedia )〕 although the star Epsilon Tauri is potentially more massive.〔(【引用サイトリンク】 work=The Extrasolar Planets Encyclopaedia )〕 == HD 13189 b == HD 13189 b is an exoplanet or brown dwarf with mass ranges from 8 to 20 Jupiter mass. This object is located at a mean distance of 277 Gm (1.85 AU) from the star, taking 472 days to make one elliptical orbit. This object was discovered in Tautenburg, Germany in 2005.〔( A Giant Planet Around The Massive Giant Star HD 13189 )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「HD 13189」の詳細全文を読む スポンサード リンク
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