Yearly Solar Declination Variation at the Equator

In this file, we see the Sun's placement, every day at about 8 AM local standard time, over the course of a year, looking eastward, from some place on the Equator. The blue sky is turned off, so as to see the Sun's passage through the zodiacal constellations.This movie starts and ends on the Autumnal Equinox, the first day of Fall. On the beginning and ending days, the Sun is directly over the Equator, as expected. This means that at local noon on these two days, the Sun will be zenial, or directly overhead.Over the course of the year, for all other days, the Sun starts out either to the right, or south of east, or to the left, or north of east. It will rise at most 23.5 degrees to the right of east (on the Winter Solstice for the Northern Hemisphere), or 23.5 degrees to the left of east (on the Summer Solstice for the Northern Hemisphere). The Sun "advances" eastward, relative to the "fixed" stars (and the corresponding zodiacal constellations), over the course of a year. What you are seeing is literally the solar declination: the angle the Sun makes between its center and the Earth's center.Of particular interest is the apparent passage of the Sun through the zodiacal constellations. Notice first that the zodiacal constellations do not correspond temporally with the astrological dates you'll find in the newspaper prediction columns. For example, at the beginning of this movie, the Sun has just "entered" the Zodiacal constellation Virgo, which means it's about a month late by the dates given in the astrology newspaper columns. So the fact that the astrologers say that something is going to happen to you because the Sun is "in" your sign is ludicrous, because the Sun is not in fact "in" your sign. This is over and above the dubious and unscientific claim that the Sun could do something to you when it is "in" your sign. The intriguing question for me is why is Sun's placement in the zodiacal constellations a whole month off from what the astrologers claim in the newspapers. See if you can figure that out.

The other interesting point is that the Sun's "orbit around the Earth" (the Ecliptic) passes through not twelve but thirteen zodiacal constellations! ( I hope that you don't suffer from triskaidecaphobia.) About a quarter of the way through the movie, the Sun passes out of Scorpius (not Scorpio), goes into a mystery constellation, and then enters Sagittarius. What is the name of the mystery constellation?

If you're striking out on these two questions, go here.