A group of comets residing mainly near the Plane of Earth's orbit around the sun. All the planets except Mercury and Pluto have orbits in nearly the same plane. The Sun's axis is tilted at an angle of 7 °15' to the ecliptic, which has been proposed as evidence the Sun was originally part of a binary star system. at distances of 34-45 The astronomical unit for length is described as the "mean" distance (average of aphelion and perihelion distances) between the Earth and the Sun. Though most references state the value for 1 AU to be approximately 150 million kilometers, the currently accepted precise value for the AU is 149,597,870.66 km. The from the Our parent star. The structure of Sun's interior is the result of the hydrostatic equilibrium between gravity and the pressure of the gas. The interior consists of three shells: the core, radiative region, and convective region. Image source: http://eclipse99.nasa.gov/pages/SunActiv.html. The core is the hot, dense central region in which the.