One of a grouping of five disparate stars in the northwestern parts of Hydra. Though widely separated in space, as seen from Earth the stars around Delta Hydrae appear to form a wedge-shaped structure which represents the head of Hydra the Sea Monster, whose body snakes away far to the east across the celestial sphere. Delta Hydrae and the 'head' formation fall very close to the Hydra's northern border, placing them directly southward from Cancer the Crab, and directly eastward from brilliantProcyon in Canis Minor.
Delta Hydrae is a rapiidly-rotating whitestar some 177 light years from the Sun. Though a main sequencestar like the Sun, it is considerably hotter and more energetic, being approximately twice the Sun's temperature and more than forty times its luminosity. Delta Hydrae is thought to have at least one companion star, an orangedwarf designated Delta Hydrae B. Unusually for a star of its type, Delta Hydrae is a source of X-ray emissions, which are thought to be produced by its companion, or possibly by a third, unconfirmed, dwarfstar in an extremely close orbit around the whiteprimary.