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Beta Canis Minoris (β CMi, β Canis Minoris) is a star in the constellation of Canis Minor. In the night sky it is notable for its proximity to the prominent star Procyon. It has the traditional name Gomeisa, which comes from the Arabic ''al-ghumaisa’'' "the bleary-eyed (woman)",〔 short for مرزم الغميصاء ''mirzam al-ghumaisa’'' "girdle of the bleary-eyed one". In Arabic, the short form would be identical with the name of Procyon. In Chinese, (), meaning ''South River'', refers to an asterism consisting of β Canis Minoris, Procyon and ε Canis Minoris.〔 ''中國星座神話'', written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.〕 Consequently, β Canis Minoris itself is known as (, (英語:the Second Star of South River).)〔 (香港太空館 - 研究資源 - 亮星中英對照表 ), Hong Kong Space Museum. Accessed on line November 23, 2010.〕 ==Properties== From parallax measurements, the distance to this star is about .〔 It has an apparent visual magnitude of 2.89,〔 making it easily visible to the naked eye. Beta Canis Minoris has about 3.5 times the Sun's mass and is rotating rapidly with a projected rotational velocity of ,〔 which gives a lower bound on the azimuthal rotational velocity along the star's equator. The actual rotation rate may be about once per day.〔 The stellar classification of this star is B8 Ve.〔 A luminosity class V star belongs on the main sequence, which means it is generating energy through the thermonuclear fusion of hydrogen at its core. The star is radiating this energy from its outer envelope at an effective temperature of 12,050 K,〔 giving it a blue-white hue typical of B-type stars.〔 An 'e' classification indicates that the spectrum contains emission lines, which means this is a Be star that is surrounded by a thin, circumstellar disk made of gaseous material ejected from the star. This hot, gaseous disk is about three times the radius of the star.〔 Beta Canis Minoris shows little variation in brightness, but it does display changes in the hydrogen emission coming from the gaseous disk. Examination with the Canadian MOST space telescope reveals low amplitude changes in luminosity from the star. This variation has a cyclic pattern formed from multiple overlapping frequencies, with the dominant frequencies being 3.257 and 3.282 cycles per day. As such, it belongs to a class called slowly pulsating Be stars, or SPBe.〔 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「Beta Canis Minoris」の詳細全文を読む スポンサード リンク
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