Delta Andromedae

Delta Andromedae (δ And, δ Andromedae) is a multiple star system in the northern constellation of Andromeda. Based upon parallax measurements, it is located at a distance of approximately 105.5 light-years (32.3 parsecs) from the Earth.

This is a long-period spectroscopic binary with an orbital period of approximately 15,000 days (41 years) 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.