1 The absolute magnitude of a star is a measure of the star's luminosity or its intrinsic brightness. 2  Its the brightness of a star if it were placed at a distance of 10 parsecs.3  The apparent brightness of a star is the star's brightness as it appears in the sky and thus is related to how far away the star is. The absolute magnitude of a star is a measure of the star's luminosity or its intrinsic brightness. 2  Its the brightness of a star if it were placed at a distance of 10 parsecs.
The cores of all four jovian planets are made of some combination of rock, metal and hydrogen compounds. Jupiter and Saturn have similar interiors, with layers extending outward of metallic hydrogen, liquid hydrogen, gaseous hydrogen, and topped with a layer of visible clouds.ll four jovian planets have rings, although only Saturn's rings are easily visible from Earth. Rings are composed of countless small pieces of rock and ice, each orbiting its planet like a tiny moon. The rings look flat because the particles all orbit in essentially the same plane.
Terrestrial and Jovian Planets. With the exception of Pluto, planets in our solar system are classified as either terrestrial (Earth-like) or Jovian (Jupiter-like) planets. Terrestrial planets include Mercury, Venus, Earth, and Mars.These planets are relatively small in size and in mass.hey are sometimes called gas giants because they are large and made mostly of gases. Small amounts of rocky materials are only found deep in the cores of Jovian planets. In the solar system, Jovian planets are located farther from the sun than terrestrial planets, and are therefore cooler.