· · · ·

A faint yellow-white star that lies to the north and west of the main body of Orion, falling eastward of Taurus' Hyades. It forms a small triplet in the sky with two nearby stars of similar magnitude: 11 Orionis and HR 1684. Based on older parallax measurements, this star was thought to lie 500 light years or more from the Solar System, but the recent Gaia data places it somewhat closer than this, at a distance of some 331 light years.

The star itself is a subgiant of the bright yellow F-type spectral class, nearly three hundred times as luminous as the Sun. It has at least one companion star and perhaps more, but the structure of the 15 Orionis system is not yet fully understood.

15 Orionis belongs to a select band of stars that lie at the poles as viewed from the various planets of the Solar System (as Polaris marks Earth's Northern Celestial Pole). Most of the planets are oriented at broadly similar angles to the Ecliptic so, like Earth, their pole stars tend to be in the far north and south of the Celestial Sphere. The notable exception is Uranus, whose poles are inclined to nearly 90° and whose pole stars therefore lie near the Celestial Equator. 15 Orionis is the southern pole star as seen from Uranus (while the planet's north pole star is Sabik in Ophiuchus on the other side of the sky).

Indexes

Related Entries