Alpha Indi - The Persian

Alpha Indi is the brightest star in the modern constellation Indus, the Indian, at magnitude 3.11. It is so far south that it just skims the horizon at mid-northern latitudes, and is not well known. The star one of the few found within the modern constellations that carry proper names. Alpha Indi was named "The Persian" by Jesuit missionaries during the late 17th century, apparently a mistranslation of the Chinese asterism Pe Sze in which the star lies.

Properties and Companions

The Persian is a class K0 III orange giant that has a temperature of 4860 K. At a distance of 101 light years, it has a luminosity 62 times the Sun's, and a radius 11 times solar. Containing 2 to 3 solar masses, it is a dying star fusing its core helium into carbon and oxygen. It is among a class of "super-metal-rich" stars, with a iron enhancement over twice the Sun's. Such stars were apparently born in interstellar clouds located inside the Sun's path around the Galaxy, that have been enriched by high rates of stellar evolution.

The Persian also has a pair of dim companions. From their brightness (12th and 13th magnitude), they must be low-mass class M red dwarfs, each at least 2000 AU from the star, and on nearly opposite sides; both take at least 50,000 years to orbit the Persian.

[Adapted from STARS by Jim Kaler, Professor Emeritus of Astronomy, University of Illinois]