Gyrd

Gyrd's synodic orbit is its path around Harb, the star that it orbits, relative to the barycenter of the orbit around Gyrd and Harb, which is located within Harb. Gyrd's orbit is influenced greatly by the orbit of Harb and Orzk around their common barycenter, which takes seven and a half times as long as Gyrd's synodic orbit around Harb. As a result, Gyrd can be thought of as having both a synodic orbit and a quattoural cycle.

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Gyrd's mean orbital distance from Harb is approximately 242,000,000 kilometers from barycenter of Gyrd's orbit around Harb. Two factors prevent Gyrd from having a perfectly circular orbit. One factor that prohibits Gyrd from having a perfectly circular orbit is the fact that Gyrd's synodic orbit is somewhat octagonal in shape. Gyrd is closer to the barycenter of its orbit around Harb at each solstice, at each equinox, and at the midpoint between any solstice or equinox and the following solstice or equinox than at any adjacent midpoint between a solstice or equinox and either adjacent midpoint between a solstice and an equinox. Because of the octagonal nature of Gyrd's synodic orbit, Gyrd can be thought of has having eight minor perihelions and eight minor aphelions each synodic year. The other factor that prohibits Gyrd from having a perfectly circular orbit is the quattoural cycle, fourteen Gyrdian synodic years in length, caused by Harb and Orzk orbiting a common barycenter. At the equinox three and three-quarter Gyrdian synodic years, and at the equinox eleven and one-quarter Gyrdian years, following the solstice that begins the quattoural cycle, which is a winter solstice in Gyrd's northern hemisphere, Gyrd is at major perihelion, or the closest that Gyrd comes to Harb at any point in a seven and one-half Gyrdian year period, and, at the midpoint of a quattoral cycle and at the solstice that begins a new quattoural cycle, Gyrd is at major aphelion, or the furthest Gyrd comes to Harb at any point in a seven and one-half Gyrdian year period. While, due to the quattoural cycle, neither minor perihelions nor minor aphelions are of uniform distance between Gyrd and Harb, Gyrd is approximately 236,000,000 kilometers from the barycenter of Gyrd's orbit around Harb at major perihelion and approximately 248,000,000 kilometers from the barycenter of Gyrd's orbit around Harb at major aphelion. This puts Gyrd's orbit wholly within the outer half of Harb's circumstellar habitable zone.

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As viewed from Gyrd's north geographical pole, Gyrd rotates in an anticlockwise direction. The inclination, or the orbital tilt, of Gyrd's synodic orbit relative to Harb's equator is approximately five degrees. As Harb appears as a disk, not a point, of light from Gyrd, and the inclination of the orbits of Harb and Orzk relative to the invariable plane of the barycenter that Harb and Orzk orbit are each approximately zero degrees, A total binary eclipse of Orzk by Harb as viewed from Gyrd occurs every seven and one-half Gyrdian years.

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The mean Gyrdian synodic year within any quattoral cycle is 472.2475 mean Gyrdian synodic days in length. In years in which Gyrd has a major perihelion, the Gyrdian synodic year is approximately 472.24 mean Gyrdian synodic days in length. In years in which Gyrd has a major aphelion, the Gyrdian synodic year is approximately 472.255 mean Gyrdian synodic days in length. Due to Gyrd's rotation, which is explained in more detail in the following section of this page, the Gyrdian synodic day is noticeably longer than real-life Earth's synodic day.