Ophiuchus - November 2005

Wait a minute!  Why is the Sun found in Ophiuchus at all?  Is THAT a constellation of the Zodiac?  We don’t see horoscopes for Ophiuchus as a Birth Sign!

The reason for this is that, beginning in 1930, astronomers “redistricted” the constellation of SCORPIO into a smaller “box” in the sky, and added OPHIUCHUS to the list of Zodiac constellations So, persons born between November 30th and December 18th should now recognize Ophiuchus as their “sign”!

What’s the explanation?

Well, the large summer constellation of Ophiuchus (the Snake Handler) has been recognized in the sky for thousands of years.  Ophiuchus appears as a large, slightly narrow pentagon of stars and traditionally carries a long snake wrapped around his body.  His starry snake, separated into two parts because it is partly “behind” Ophiuchus’ body, forms the constellation of SERPENS (that’s another story!).

And, you see, originally the constellations were simply groupings of stars which traced out cartoon-like outlines (stick figures) of familiar objects in the sky.  Often, the edges and other features of these figures were represented by individual stars.  Many ancient cultures knew the year was nearly 12 months (lunar cycles) long, so they similarly divided up the great circle of the Sun’s path (“Ecliptic”) through the stars into 12 groups of stars – or one star grouping for each month.  The collection of the 12 groups of stars became known as the 12 Constellations of the Zodiac.  Traditionally, each of these 12 Constellations “ruled” an exact one-twelfth of the sky (and the Sun, which “visited” each constellation for one month per year).

However, even a casual look at the sky regions of the Zodiac at night will show that the Zodiac star groups are not of equal size.  Nor are the stars equally spaced along the Zodiac!  In some places there are large “blank spaces” between recognizable star patterns.  However, in the interest of uniformity, the ancients still divided the Zodiac into 12 EQUAL divisions in celestial Longitude around the Zodiac.

Also, while the ancients did know that the Sun actually only traveled through the head but not the body of SCORPIO the Scorpion, the scorpion pattern of stars is JUST TOO SIMILAR to that of a real scorpion to be ignored!  So, Scorpio was featured as an equal constellation in all the ancient Zodiac star groups.

In the very earliest sky maps, areas of sky outside the Zodiac with only faint stars were shown simply as gaps between the traditional constellations.  Later, after the invention of the printing press, maps and atlases could be commercially published.  Unfortunately, these all showed different boundaries, spellings and even names for the familiar constellations.  Those authors also began to invent new constellations as the Southern Hemisphere was explored and charted.

Soon, the “empty” regions in the Northern sky began to be filled with newer constellations honoring kings, “modern science” and even ordinary objects. (This is how the constellations of SCUTUM, SEXTANS, MICROSCOPIUM & TELESCOPIUM [honoring Sobieski’s Shield, the Sextant, the Microscope and the Telescope] came into being.  MUSCA (the fly), TUCANA (the Toucan), HOROLOGIUM (the clock), and several other constellations most of us will NEVER recognize were also invented in this way!

Astronomers, though, were mostly indifferent about the actual boundaries of the constellations.  They continued to happily study the stars and to map “their” skies using imaginary grids based on Celestial Longitude (“Right Ascension”) and Celestial Latitude (“Declination”).  In about 1860, however, astronomers began to use the new science of photography to record the stars.

When astronomers collected large photographic databases of (for example) Double Stars, Nebulas, Variable Stars, etc., it was apparent a new system was needed to name objects and locate them in the sky.  On the one hand, objects identified only by Celestial Longitude (Right Ascension) and Celestial Latitude (Declination) were more difficult less appealing when described in the popular press.  On the other hand, there was increasing popular confusion over constellation names, locations and star locations.

Several attempts to standardize constellation positions and boundaries occurred in the 1800s.  These sparked debate inside and outside the astronomical community!  (Note today that efforts to change Congressional Districts or city/county boundaries are also VERY controversial!).

Finally, the International Astronomical Union (or IAU) formally voted and agreed on a permanent set of constellation boundaries and maps which took effect in 1930.  Today:
1) EVERY part of the sky formally belongs to one and only one Constellation
2) Constellation Boundaries are ONLY described “on the record” by lines of Right Ascension and Declination.

The most controversial change “redistricted” SCORPIO into a smaller “box” in the sky, and added OPHIUCHUS to the list of constellations crossed by the Sun during the year.  So, beginning in 1930, Ophiuchus became recognized as the 13th Constellation of the Zodiac (it always was, but it received the formal honor in 1930).  So, persons born between November 30th and December 18th should now recognize Ophiuchus as their “sign”!