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One of the stars that forms the shape of Serpens Caput, the western part of the divided constellation Serpens that represents the Serpent's head, lying eastward of Arcturus in the sky. Despite its 'Beta' designation, this is not Serpens' second brightest star but actually its fifth, following Alpha (Unukalhai), Eta, Mu and Xi Serpentis or Nehushtan, though none of these exceeds third magnitude.

Beta Serpentis is thought to belong to the Ursa Major Moving Group, implying that it shared an origin, several hundred million years ago, with most of the stars that make up the Plough or Big Dipper formation. These stars are now scattered across the nearby regions of the Galaxy (Beta Serpentis is a little more than 150 light years from the Sun) and now appear in widely separated parts of the sky.

Structurally Beta Serpentis is a highly complex system. It is at least a ternary or triple system, but may have as many as five components. At the heart of the system is a white subgiant star, Beta Serpentis A, which is about three times as massive as the Sun. Orbiting this 'A' star are two companions designated B and C, and beyond them, in extremely distant orbits, are potentially two further companions. There are indications that one of these possible companions, Beta Serpentis D or HD 140665, may itself be a binary star, adding further to the complexities of the Beta Serpentis system.


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