TYCHOS = the term I chose for my cosmic model which, of course, is heavily inspired by Tycho Brahe’s model. The final “S” stands for my first name, Simon — since I humbly consider to have completed Brahe’s work.
Tychosium : the interactive planetarium developed by myself and IT-programmer Patrik Holmqvist.
The PVP orbit = The Polaris-Vega-Polaris orbit of the Earth = 113,230.656km in Ø — and 355,724,597 km in circumference
The PVP constant: the percentage-ratio of Earth’s orbital speed in relation to the Sun’s orbital speed : 0.00149326 %.
(The Sun travels at 107,226km/h — whereas Earth travels, in the opposed direction, at 1.601169 km/h.)
TGY = TYCHOS Great Year = 25,344 years = the full time period for the Earth to complete one PVP orbit
ACP = Annual Constant of Precession = 51.1363 arcseconds. This is the TYCHOS-computed, true angular amount by which the stars are drifting (Eastwards in relation to the Sun) each year, as a consequence of Earth’s 1-mph-motion around its PVP orbit.
TMSP = our Moon’s True Mean Synodic Period = 29.22 days. This is the TYCHOS-computed, true (average) synodic period of our Moon.
moon: in lower-case, a satellite of a planet; otherwise capitalized “Moon” being the satellite of Earth.
AU = Astronomical Unit = Average Earth-Sun distance = 149,597,870.7 km (or roughly 149.6 Mkm)
RA = Right Ascension : the celestial equivalent (used in astronomy) of terrestrial longitude. Wikipedia on “Right ascension”
DECL = Declination : the celestial equivalent (used in astronomy) of terrestrial latitude. Wikipedia on “Declination”
360° = 1,296,000 arcseconds = 1,440 minutes (our celestial sphere) = 24 hours = 100% of 1 circle or revolution. The sky can be divided into a number of degrees, arcseconds, minutes or hours of RA. It can sometimes get confusing — but that’s astronomy for you!
Sidereal period: a celestial body completes a “sidereal” period each time it aligns again with a given star.
Synodic period: a celestial body completes a “synodic” period each time it aligns again with the Sun.
Perigee: closest transit point of a body with respect to Earth
Apogee: furthest transit point of a body with respect to Earth
Perihelion: closest transit point of a body with respect to the Sun
Aphelion: furthest transit point of a body with respect to the Sun
Inferior conjunction: when a body (e.g. Venus) is aligned with the Sun while transiting closest to Earth
Superior conjunction: when a body (e.g. Venus) is aligned with the Sun while transiting furthest from Earth
Prograde: a celestial body is said to be “in prograde mode” when it moves in the same direction as the Sun.
Retrograde: a celestial body is said to be “in retrograde mode” when it moves in the opposed direction of the Sun.
Precession: “precession” is just a fancy word for “drift”: in astronomy, a celestial body is said to be “precessing” whenever it is observed to drift over time in relation to other celestial bodies. In the TYCHOS, the stars “precess” over time (in relation to our ‘time-keeper’, the Sun) as a consequence of Earth’s 1-mph-motion. This stellar drift is known as the “equinoctial precession”, since the stars are observed to slowly drift (Eastwards) in relation to our terrestrial equinoxes.
Equinox: Please read Wikipedia’s “Equinox” entry
Apsidal precession: Please read Wikipedia “Apsidal precession” entry
Binary system: a system wherein two celestial bodies orbit around each other around a common barycentre. Up to 85% (or more) of our visible stars are, in fact, binary systems composed of a large and a smaller object. More often than not, binary systems also feature additional bodies (moons, planets) hosted within or outside of the system (so-called “circumbinary” bodies).
Circumbinary: a circumbinary body circles around any given binary system, as described above.