Glosario - Z

Zenith is the point on the sky that is directly overhead, from the perspective of a particular location on the Earth.

Zero-age main sequence (ZAMS) is the sequence of positions along the Hertzsprung–Russell diagram achieved by newly formed, chemically-homogeneous stars that have finished contracting and have reached hydrostatic equilibrium, with energy being derived solely from nuclear fusion.[24]

Zodiac is the apparent path of the Sun across the celestial sphere as seen from Earth's orbit. It crosses a band of twelve Zodiac constellations, through which the Moon and visible planets are seen to travel.