It's a classic bar pickup line...."What sign are you?" (The classic answers include "Maternity Ward" and "No Trespassing"). Chances are whatever sign you say you are, you aren't.

First, let's agree on what a "sun sign" is. As you might guess, a sign is a constellation. A sun sign must have something to do with the sun appearing with a constellation. So we should be able to easily agree on the definition of a sun sign: The constellation the sun is in on the day you were born. Agreed? Good.

While the newspapers may list 12 equally sized star groupings for horoscope lovers, the astronomical fact is that the Sun passes through 13 constellations and touches a 14th. This automatically means that the sun can not possibly spend 30 days in each constellation!

The sizes of the constellations are quite diverse, i.e. the sun does not spend equal amounts of time in each star group but spends as few as seven days to as much as 45 days in a constellation. Furthermore, the start dates of entry into each constellation do not mesh with horoscope dates because the original constellation borders were those of several thousand years ago. The earth's wobble - precession - has caused those borders to shift along the ecliptic, the path of the sun in the stars as seen from earth.

Below are the constellations that house the sun, and the dates the Sun enters and leaves each, on average. Because of leap years and the non-integer number of real days in a year, the dates can shift either way by about a day.

		     Dates Sun Is 
ConstellationIn The Constellation    # of Days
Sagittarius	Dec 18 - Jan 18		32
Capricornus	Jan 19 - Feb 15		23
Aquarius	Feb 16 - Mar 11		24
Pisces		Mar 12 - Apr 18		38
 Cetus		 Mar 26			< 1
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

What about the 13th sign, the one at the bottom of the table? You have better odds at being a Serpent Bearer (that's what Ophiuchus is) than a Scorpion. Only a piece of the latter intersects the ecliptic while the Sun actually spents nearly three times as long traversing one of the good Serpent Holding Doctor's legs. You won't ever see a horoscope for being an Ophiuchan, there is apparently no future in it....

The path of the sun, the ecliptic, does not actually enter the constellation of Cetus but simply touches a point of its boundary between it and Pisces. The Sun, however, is a disk in the sky, not a point, and therefore part of the Sun (up to half the disk) strays into the area of the constellation for not quite a full day. You have to have a whale of a lot of luck to be born under the "sign" of Cetus, the Whale (or Sea Monster, prominent in the legend of Andromeda and Perseus, but that's a story for another night....).

This article originally appeared in Hermograph Press' now out-of-print publication The AlterNETive Searcher but has been a feature in many To Teach The Stars Workshops.