Delta Capricorni is the brightest star in the constellation of Capricornus, the Sea Goat. It is a binary star system whose components are seen to eclipse each other, known as an eclipsing binary. The baseline apparent magnitude is 2.81, and during the primary and secondary eclipse it dims to 3.05 and 2.90, respectively. The system lies at a distance of 38.7 light-years (11.9 pc), based on parallax measurements. The two components of this system are designated Delta Capricorni Aa and Delta Capricorni Ab. The former is the primary and has the proper name Deneb Algedi, pronounced ; the traditional name of the system. Delta Capricorni is positioned 2.6 degrees south of the ecliptic and can be occulted by the Moon, and (rarely) by planets.

Closest relatives