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November 2005 Feature: The Pawnee Star Calendar

Oftentimes, November is called the month of the Pleiades, because this most famous of star clusters adorns the November night sky from dusk till dawn. The Pleiades star cluster -- sometimes referred to as the Seven Sisters -- is a misty-looking dipper-shaped formation of six stars that marks the shoulder of the constellation Taurus the Bull. Stories abound worldwide on the mystery of the lost Pleiad.

By one account, the missing Pleiad ran off with Mizar, the middle handle star of the Big Dipper. These two stars can be seen snuggling next to one another on a clear, dark night. If you can't see Mizar's companion star -- Alcor -- with the eyes alone, try binoculars.

Centuries ago, in what is now Nebraska, the historic Pawnee watched the stars passing above the smoke holes of their lodges, these smoke holes serving to show the clock and calendar as the handiwork of the stars. In late autumn, they noted when the Pleiades shone through their smoke holes at midnight. The Pleiades' midnight culmination, which happened but once a year, was a sure sign that the winter solstice -- the shortest day of the year -- was only one month away. The Pleiades watched over the season of short days and long nights.

One half year later, the Pawnee watched for the return of the Circle of Chiefs -- the C-shaped configuration of stars that we now call Corona Borealis, or the Northern Crown. The Circle of Chiefs -- the counterpart to the Pleiades star cluster -- appeared above the smoke hole at midnight in late spring -- or one month before the summer solstice. The Circle of Chiefs ruled over the season of long days and short nights.

Daily Motions

On a daily basis, the Pleiades and the Circle of Chiefs trade places in the sky every 12 hours.* The Pleiades star cluster culminates at midnight on or near November 21. Therefore, even though you can't see it, the Circle of Chiefs transits at its highest point in the sky (over the smoke hole) around noontime on this date.

At nightfall in the later part of November -- at 6 p.m. local time or so -- see if you can discern the Circle of Chiefs in your northwest sky, and the Pleiades (fairly close to Mars) in the northeast sky. Then, 12 hours later, after the Earth has rotated some 180 degrees eastward on its axis, and the stars have swung westward half circle, see if these two star formations don't trade places in the early morning hours before sunrise.

The Pleiades as an Agricultural Calendar

The stars return to the same place in the sky about 4 minutes earlier with each passing day, or 2 hours earlier with each passing month. A month or so before the spring equinox, the Pleiades cluster passes over the smoke hole at evening dusk, and the Circle of Chiefs transits over the smoke hole at morning dawn. This announced to the Pawnee that it was time to prepare the fields for the spring planting.

Thereafter, the Pleiades' daily transit over the smoke hole became lost to the light of the Sun -- not to return to visibility again till near the time of the autumn equinox. The Pleiades' first dawn appearance over their smoke holes alerted the Pawnee that the time had come to start harvesting their crops.

This gives you a glimpse at the workings of the Pawnee clock and calendar, this stellar method of timekeeping showcasing the poetry of motion and the natural rhythm of time.

* More precisely, I should say 12 sidereal (stellar) hours, which is about 2 minutes shorter than 12 solar hours (time as measured by the Sun).

copyright 2005 by Bruce McClure

Reference: They Dance in the Sky by Jean Guard Monroe and Ray A. Williamson

October 2005 Feature * December 2005 Feature

Halloween 2005 Feature: Arcturus, Ghost of Summer Sun

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