At magnitude 2.39, Alpha Phoenicis is the brightest star in the constellation Phoenix, a modern constellation named by southern hemisphere explorers and first noted in Bayer's Uranometria. The star has the traditional name Ankaa, a late application of the Arabic word for "phoenix". However, the stars in the area were considered by the medieval Arabs to be a dhow, or small boat, and so another popular name for the star is Nair al-Zaurak, meaning "the bright one of the boat" in Arabic.
Properties and Companion
Ankaa is a yellow-orange class K0 III giant at a distance of 77 light years. It radiates 86 solar luminosities, with a surface temperature of about 4800 K. With a mass of around 2.5 suns, and a radius 13 times solar, the star seems to be in its stable helium-fusing stage, from which it will eventually become a brighter and larger red giant.
Ankaa has a rotation speed similar to the Sun's - about 2 km/sec at the equator. Even so, Ankaa might take up to a year to make a full rotation due to its large size. The spin is responsible for some activity that makes the star a modest X-ray source. Ankaa's space velocity is high, 88 km/sec relative to the Sun.
Ankaa has a small stellar companion, detected spectroscopically. Orbiting eccentrically at an average distance of 7 AU, the companion takes 10.5 years to make a full circuit. Currently little else is known about the companion.
[Adapted from STARS by Jim Kaler, Professor Emeritus of Astronomy, University of Illinois]