Forty seven is a prime number.

As a number of lunar months it is only slightly longer than four eclipse years, i.e. 1.45773 days or one day one eleven hours of 1/24th of a day. The octon appears strongly present in the Crucuno monument (see second Crucuno article), where 47 lunar months were counted using a unit of 27 feet, starting at the dolmen and ending in the rectangle.

It can be found in the 235 (5 x 47) lunar months of the 19 solar year Metonic period, in which the sun, moon and stars give a very similar configuration.

Since the best eclipse repetition period, the Saros (of 19 eclipse years), precedes the Metonic by exactly 12 lunar months (the lunar year), then the Metonic period is a significant eclipse cycle in its own right, different only by the difference in duration of the eclipse year and lunar year: 354.367 - 346.62 = 7,747 days. The Kerzero alignments can be interpreted to incorporate a counting of the Metonic period using units involving 47 lunar months, perhaps in search of larger astronomical coincidences - coincident by nature but governed by the differences between the solar year, lunar year and eclipse year, the lunar month, all in solar days, and the sidereal day length.

Title Created Date
Lunar Counting from Crucuno Dolmen to its Rectangle 24 February 2018
Another Rectangle near Kerzerho 15 March 2018
Comparing Erdeven and Le Menec Alignments 27 March 2018