[14] The European astronomer Tycho Brahe dubbed it Cor Hydræ, Latin for 'the heart of Hydra'.

[3] Its estimated age is 420 million years[8] and it has evolved away from the main sequence to become a giant star with a spectral classification of K3 and luminosity class III.

[3] The angular diameter has been measured using interferometry, after correction for limb darkening, it yields a value of 9.58±0.08 mas.

[6] Alphard's spectrum shows a mild excess of barium, an element that is normally produced by the s-process of nucleosynthesis.

The multi-periodic oscillations make HD 81797 (Alphard) an object of interest for asteroseismologic investigations.