81_Aquarii
81 Aquarii
Star in the constellation Aquarius
81 Aquarii is a star in the constellation of Aquarius. It has an orange hue and is barely visible to the naked eye with an apparent visual magnitude of 6.23.[2] 81 Aquarii is its Flamsteed designation. The star is located at a distance of approximately 451 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +1.6 km/s.[1] It is positioned near the ecliptic and thus is subject to lunar occultations.[5]
This is an aging giant star with a stellar classification of K5 III,[3] indicating it has exhausted the supply of hydrogen at its core then cooled and expanded off the main sequence. The stellar spectrum displays strong lines of cyanogen.[6] It presently has 18 times the radius of the Sun and is radiating 102 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,324 K.[1]