Hamilton Amateur Astronomers
Maintained by Grant Dixon
In light of the different entertaining topic surrounding Astrology by Denise, a guest of HAA's April General Meeting, I have chosen this month to stage a slightly different performance. I will look at the Precession of the First Point of Aries, the Equinoxes and Solstices. Their shift pattern is in reference to the 26,000 yr. cycle (25,765 yrs.) of the Earth's Precession rotation around the sun.
Both subjects originated about 2000 years ago but were not separate. Astrology/Astronomy used ecliptic stars. The same Zodiac is still used today although it has changed over the years due to Precession and our own Earth's WOBBLE. The term "wobble" is used loosely to describe the motion of the Earth, as in a top spinning. At present, Polaris is our North pole star but thousands of years from now, that will change and eventually we will have a new pole star. True North is about .8o off Polaris. The following definitions will help you understand what precession is all about;
PRECESSION (of Earth) - (NOT to be confused with Wobble) A slow, conical motion of the Earth's axis of rotation, caused principally by the gravitational torque of the moon and sun on the Earth's equatorial bulge.
-Lunisolar precession, precession caused by the moon and sun only;
-Planetary precession, a slow change in the orientation of the plane of the Earth's orbit caused by planetary perturbations;
-General precession, the combination of these two effects on the motion of the Earth's axis with respect to the stars.
PRECESSION (of Equinoxes) - (NOT to be confused with Wobble) Slow westward motion of the equinoxes along the ecliptic that results from precession.
WOBBLE - Wandering of the poles; variation of latitude. It is extremely slight and does not effect precession on the whole.
PROPER MOTION - The angular change in direction of a star per year as seen from the sun.
By definition, the first point of Aries has 0 RA. and 0 DEC. Because procession shifts the points position over time, the co-ordinates of all the stars and other objects in the sky also shift. Hence, new Star Atlases every 50 years. Between 1800 BC and AD 1, the Zodiac was invented and the Sun lay in Aries at the time of the Vernal Equinox, named "the first point of Aries". It still bears this name, even though the Sun on the day of the Equinox has now moved into the Constellation Pisces. The first point of Aries will continue to shift and in another few hundred years the Sun will move into Aquarius. Giving approximate millenniums (1 millennium = 2000 yrs.) the sun lay in the following constellations at the Vernal Equinox:
B.C. 6000 - 4000 Gemini 4000 - 2000 Taurus (4380-2220 BC) 2000 - 1 Aries - Birth of Christ HALT ASTROLOGY/ASTRONOMY - ERA DID NOT ADVANCE - STAYED IN ARIES A.D. 0 - 2000 Pisces 2000 - 4000 Aquarius
At 0 A.D. there was a halt in astrology/astronomy. The creators of myth, ancient gods and religions disappeared. Christianity was established and no one was able to manipulate the celestial vision. Instead of going from Aries into the era of Pisces, everything stayed the same except the apparent motion of the sun which shone and still shines in Pisces at the Vernal Equinox. The sun does not move into Constellations. The Earth moves around the sun and it is due to precession that the sun appears to change position on the ecliptic line. Astronomers separated from Astrologers when Procession was realized and Astronomy was recognized as a science. Astrologers still use the stars of 2000 years ago, an unchanged ecliptic Zodiac. This means that modern astrologers use a zodiacal model that has been outdated for almost two thousand years. The current Zodiac actually has 14 Constellations. Ophiuchus - the 13th and Cetus - the 14th. Ophiuchus has obtained a substantial 2 week time slot on the ecliptic and Cetus has now snuck on for 2 days interrupting Pisces. Long before Hipparchus ever made his star charts, early astrologers had named the 12 zodiacal constellations. Even then, they were shrouded in mythology and the symbolism of astrology. Originally, the division of the zodiac into 12 constellations, or signs, may have emerged when early skywatchers noticed that Jupiter took 12 years to complete its orbit around the ecliptic, and spent one year in each zodiac constellation. Jupiter is the brightest planet seen throughout the night and must have been an object of great interest in early times. (Venus is brighter but is only visible for a few hours before sunrise or after sundown.) Far back in ancient antiquity, the number 12 became a very powerful symbol - 12 apostles, 12 Biblical patriarchs, 12 jurors and of course, 12 months in a year. This final division is most likely a product of the lunar orbit, which travels around Earth 12 times a year, with 12 days left over. As you can see, the stars perform many other fascinating dances which are not visible to us. However over great spans of time we have been able to see slight changes of these shifts. Also, we can now track backwards and forward in time with great accuracy to see what precession has and will bring our way.
**BC 4000 - 2000
TAURUS LEO SCORPIUS AQUARIUS sp.eq. sum.sol. aut.eq. win.sol.
**BC 2000 - 0 (birth of Christ - Zodiac created)
ARIES CANCER CAPRICORNUS LIBRA sp.eq. sum.sol. aut.eq. win.sol.
PISCES GEMINI VIRGO SAGITTARIUS sp.eq. sum.sol. aut.eq. win.sol.
Aquarius TAURUS LEO OPHIUCHUS sp.eq. sum.sol. aut.eq. win.sol
We can see relics of the old Equinoxes right here on Earth with the names of our Lines of Tropic. Currently they are the Tropics of Cancer & Capricorn. If we apply precession they should be The Tropics of Gemini & Virgo.
Ev Butterworth
Hamilton Amateur Astronomers
Maintained by Grant Dixon
