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Proper NameNone
Bayer DesignationDelta Andromedae
Flamsteed Number31 Andromedae
HR (BSC)165
Right Ascension0h 39m 20s
Declination+30° 51' 40"
Distance106 light years
32 parsecs
MagnitudeApparent: +3.26
Absolute: +0.71
Spectral ClassK3III-IIIbCN0.5 orange giant
Optimum VisibilityOctober
NotesThe Delta Andromedae system consists of a binary pair of orange stars, one an evolved giant and the other a dwarf star, separated by a distance of some 11 Astronomical Units (a distance slightly greater than that of the planet Saturn from the Sun). The system has at least one further companion star in a much more distant orbit around the central binary pair.

An orange star in the southern regions of Andromeda, lying directly southward of the Andromeda Galaxy, and also directly westward of the Triangulum Galaxy in the sky. Delta Andromedae can be found roughly halfway between the two brighter stars Alpheratz (also called Sirrah) and Mirach, respectively the Alpha and Beta stars of Andromeda. At 106 light years, Delta Andromedae is only a slightly more distant from the Solar System than Alpheratz, but only about half the distance to the intensely luminous Mirach.

Imagery provided by Aladin sky atlas

Delta Andromedae is a binary, and probably multiple, system. The primary star is an orange giant more than sixteen times the diameter of the Sun, which appears to be surrounded by a circumstellar disc of material and has an orange dwarf companion star. It has at least one further companion, Delta Andromedae B, which is a red dwarf in a distant, millennia-long orbit.

A further faint star appears close by in the sky, designated Delta Andromedae C, but this does not appear to be physically related to the orange giant and its system, and its apparent proximity is more likely to be due to its line of sight from Earth.


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