A large celestial area defined by six of the brightest
stars of the winter sky. Opinion is divided over exactly which stars
define this asterism, though the best approximation of a hexagon shape seems to be
formed by Capella, Aldebaran, Rigel,
Sirius, Procyon and Castor.
Also in this region are the bright stars
Betelgeuse and Pollux, and they are often also described
as part of this winter grouping.
The Winter Hexagon is specifically associated with the northern hemisphere of Earth, and the stars that make it up are, for the most part, only clearly visible from northern latitudes. In the southern hemisphere this would in principle be the Summer Hexagon, though practically speaking only the area around Sirius would be visible to suitably placed southern observers.
The table opposite shows the seven constellations that make up the bulk of the Hexagon's area, and the major stars in each that contribute to its shape. Its southwestern borders also strictly include a small part of Lepus the Hare, and a tiny sliver of Eridanus.
On a galactic scale, the entire Hexagon represents a view outwards from the disc of the Milky Way Galaxy, through its Orion and Perseus Arms and out into the vastness of intergalactic space that lies beyond.