The Real Constellations of the Zodiac

To put astrology in the proper perspective, we can do two things to try to remedy the situation. First we must stop spreading astrological information. Yes, I believe all of us have done this even though unintentionally. The prime example and major point of this article is in reference to the band of the zodiac. Consider just the ecliptic. How often have you referred to the twelve constellations that the sun passes through during a year? The number twelve is correct only if one is using astrological constellations. There are thirteen astronomical constellations that cross the ecliptic. Whenever you refer to the zodiac use the number thirteen and name the constellations of the ecliptic (see Table #l). If someone complains that these are not the right constellations, just point out that all constellations are arbitrary and strictly artificial. The ones we use are the official constellations of the International Astronomical Union.

 

In addition to ceasing our propagation of astrological information, we can also give the public further astronomical information that will hopefully have the effect of raising questions about astrological belief and practice. Table #1 also includes the dates for which the sun is in each constellation of the ecliptic and the number of days it spends in each constellation. If someone asks you what constellation the sun is in on a particular date, use this information and mention that the answer you are giving is the astronomical constellation the sun is in on the date in question. If you cross check between the dates listed here and the standard astrological dates, you will find there are approximately only four dozen dates in common.

 

Then there is a question of the definition of the zodiac itself. In a quick survey through about ten basic astronomy texts, the definition given was either 8° or 9° on either side of the ecliptic. To be on the conservative side, Table #2 lists those constellations that come within 8° of the ecliptic. (Venus is the only naked eye planet that reaches more than 8° away from the ecliptic. ) You can quickly see that there are not 12 constellations of the zodiac but 24. At the appropriate times you can list the nontraditional constellations in which the sun, moon, or planets can be found. The current American Ephemeris & Nautical Almanac and the Atlas Coeli (or some other suitable stellar atlas with constellation boundaries marked) are all that are needed for producing this type of list.

 

If you include the orbit of Pluto which is tilted at 17° to the ecliptic, then the zodiac also includes the constellations Bootes, Coma Berenices, Eridanus, and Leo Minor. Using this information, you can have an interesting time incorporating it into shows or creating public displays. If and when astrologers complain, your interest is promoting astronomy, not astrology.

 

However, there is one caution I would like to mention. If someone asks you whether you believe in astrology, ask them what they mean before you reply. If someone gives me a definition such as "the belief and study of cosmic influences on the earth and its creatures", I can agree that such influences do exist. However, I point out that while it is obvious there are cosmic influences, especially from the sun and the moon, there is no evidence that positions of the heavenly bodies can be used to predict the actions or characteristics of individuals.

 

Table 1. Astronomical Constellations of the Ecliptic

Constellation	Dates	# of d
Sagittarius	Dec 18-Jan 18	32
Capricornus	Jan 19-Feb 15	28
Aquarius	Feb 16-Mar 11	24
Pisces	Mar 12-Apr 1	38
Aries	Apr 19-May 13	25
Taurus	May 14-Jun 19	37
Gemini	Jun 20-Jul 20	31
Cancer	Jul 21-Aug 9	20
Leo	Aug 10-Sep 15	37
Virgo	Sep 16-Oct 30	45
Libra	Oct 31-Nov 22	23
Scorpius	Nov 23-Nov 29	7
Ophiuchus	Nov 30-Dec 17	18

Table 2. Astronomical Constellations of the Zodiac

Aquarius	Cetus	Libra	Scorpius	Aries	Corvus	Ophiuchus	Scutum
Auriga	Crater	Orion	Serpens	Cancer	Gemini	Pegasus	Sextans
Canis Minor	Hydra	Pisces	Taurus	Capricornus	Leo	Sagittarius	Virgo

• The Real Constellations of the Zodiac (source)
• The Real, Real Constellations of the Zodiac
• Coordinates of the 13 zodiac constellations