Delta Andromedae
Delta Andromedae is a multiple star system in the northern constellation of Andromeda. Based upon parallax measurements, it is located at a distance of approximately from the Earth.
In Chinese, 奎宿, meaning Legs , refers to an asterism consisting of δ Andromedae, η Andromedae, 65 Piscium, ζ Andromedae, ι Piscium, ε Andromedae, π Andromedae, ν Andromedae, μ Andromedae, β Andromedae, σ Piscium, τ Piscium, 91 Piscium, υ Piscium, φ Piscium, χ Piscium and ψ¹ Piscium. Consequently, the Chinese name for δ Andromedae itself is 奎宿五 Apart from its Bayer designation, it was also given the title Delta by Elijah H. Burritt in his star atlas.
This is a long-period spectroscopic binary with an orbital period of approximately 15,000 days and an overall apparent visual magnitude of approximately 3.28. The primary of the spectroscopic binary has a stellar classification of K3 III, indicating that it is a giant star. It most likely evolved from a F-type main sequence star after consuming the hydrogen at its core. The secondary is a relatively faint K-type dwarf, which has been imaged using a stellar coronagraph. The star has two optical companions, the closest of which may be an orbiting red dwarf of class M3 with a separation of at least 900 astronomical units.
An excess of infrared emission from δ Andromedae suggested that it may be surrounded by a shell of dust. In 2003 it was determined that this is more likely a circumstellar debris disk.
