The Nautical Almanac # 55 --- Al Na'ir, The Brightest

Al Na'ir ("The Brightest") is the brightest star in the little-known constellation of Grus The Crane which flies in the skies of the far Southern Hemisphere. 

 

Although Al Na'ir has long been known as a bright star in its constellation, until around 1600 that constellation was Piscis Austrinus The Southern Fish (not to be confused with the Zodiacal constellation of Pisces The Fishes), and Al Na'ir was the brightest star in the tail of the Southern Fish (yet another Deneb!)

European explorers redrew their star maps extensively during the Age of Discovery. They mapped Grus along with the rest of the constellations collectively known as "The Southern Birds". The name was borrowed from Chinese traders who saw the asterism as a crane and called it "Ke."

The constellation of Grus The Crane was once considered part of Piscis Austrinus The Southern Fish.

Rather arbitrarily, Western astronomers assigned Al Na'ir, long known to the Arabs and the ancients, to the new constellation wherein it is indeed the brightest star. Scientists call it Alpha Gruis. 

Al Na'ir is a bright star of the Second Magnitude. It should not be confused with Zeta Centauri, another Second Magnitude star in Centaurus The Centaur, which is also called Alnair in some star almanacs. Centaurus' Alnair is not a major navigational star, but Grus' Al Na'ir is the 55th star of the Nautical Almanac.

There is debate over whether Al Na'ir is a star alone or in a multistar system, and the question of whether it has planets or is forming them goes unanswered.

Al Na'ir is a white Main Sequence star with a bluish tinge. It burns at 24,596 degrees Fahrenheit. It has four times the mass and 3.5 times the radius of the Sun. It is 101 light years away from Earth and is 520 times as bright as the Sun. It is 70,000,000 years old. In many ways it is extraordinary in its ordinariness.

The Southern Birds --- Pavo The Peacock, Tucana The Toucan, Grus The Crane and Phoenix The Firebird, along with Apus The Bird of Paradise (not shown) --- make up a crowded and far southern corner of the sky, along with Indus The Indian, and Hydrus The Male Water Snake. From Bayer's Uranometria, 1603.