Just
as Sirius marks out the neck of the Great Dog, Adhara, the nineteenth
star in the Nautical Almanac, marks out the upper hindquarters. The name
Adhara means "The Adored Daughter" in Arabic and Hebrew, though this is
often mistranslated as "The Virgins".
Adhara is a First Magnitude star, and would be the brightest in Canis Majoris were it not for Sirius. As a matter of fact, some five million years ago, Adhara was the brightest star in Earth's night sky, but just as Sirius is approaching the Earth Adhara is moving away. It is now 450 light years from Earth when formerly it was merely 34 light years away, and bright enough to cast a faint shadow on a dark night, being 15 times as bright as Venus. No other star has ever appeared as bright from Earth (excepting, of course, the Sun).
Adhara is nearly 40,000 times as bright as our Sun, and it has 13 times the mass and 14 times the radius. It burns at near 40,000 degrees Fahrenheit. It is a brilliant blue-white star which sparkles in telescopes, and emits massive amounts of ultraviolet radiation; if we could see UV, Adhara would be much, much brighter than Sirius. Its solar wind is powerful and is reshaping gas clouds and nebulae through intense ionization.
Adhara is only 22 million years old, but due to its prodigious energy output Adhara is entering the last stage of its stellar life and will explode as a supernova within the next five million years or so. It has a binary companion as seen through telescopes, but the companion, a blue-white Main Sequence star, is only 1/250th of Adhara's brightness --- still 160 times as bright as the Sun.
Adhara is a First Magnitude star, and would be the brightest in Canis Majoris were it not for Sirius. As a matter of fact, some five million years ago, Adhara was the brightest star in Earth's night sky, but just as Sirius is approaching the Earth Adhara is moving away. It is now 450 light years from Earth when formerly it was merely 34 light years away, and bright enough to cast a faint shadow on a dark night, being 15 times as bright as Venus. No other star has ever appeared as bright from Earth (excepting, of course, the Sun).
Adhara is nearly 40,000 times as bright as our Sun, and it has 13 times the mass and 14 times the radius. It burns at near 40,000 degrees Fahrenheit. It is a brilliant blue-white star which sparkles in telescopes, and emits massive amounts of ultraviolet radiation; if we could see UV, Adhara would be much, much brighter than Sirius. Its solar wind is powerful and is reshaping gas clouds and nebulae through intense ionization.
Adhara is only 22 million years old, but due to its prodigious energy output Adhara is entering the last stage of its stellar life and will explode as a supernova within the next five million years or so. It has a binary companion as seen through telescopes, but the companion, a blue-white Main Sequence star, is only 1/250th of Adhara's brightness --- still 160 times as bright as the Sun.
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