Southern Major Lunar Standstill alignment from S1, Llananno
to Drygarn Fawr cairns.
W/7.6.1 This time-lapse photograph was taken at
the southern extreme of the Moon in August 1989. The last Major Lunar Standstillhad occurred in late 1987 and the Moon's
declination
was still very high, rising and setting close to the extreme positions
of 4000 years ago.
S1, Llananno to Drygarn Fawr cairns.
W/7.6.2 Over the ruined stone circle
and cairn at
S1, Llananno the Moon is setting on Drygarn Fawr, 17.7 miles (29.5km) distant, the highest mountain in the Cambrian range which runs north/ south through the middle of Wales. One cairn
is silhouetted on the moon's track the other is to the right on the next peak. The declination difference between the two cairns is very close to 9 arc minutes, exactly the semi-amplitude of the minor wobble termed Cyclic Perturbation. As with the Northern Major Lunar Standstill alignment to Glog Hill tumuli in the opposite direction, perturbation of the lunar orbit at the standstill extreme is carefully indicated by twinforesights.
W/7.6.3 K for the S1/Drygarn Fawr alignment.
The reason we still see the far
cairn on the Moon's
disc, despite the considerable change in the position of the standstill over 4000 years, is because this alignment,
S1/Drygarn Fawr,
is arranged to show the position of the setting Moon precisely 24 hours before the true Lunar Standstill in 1700 B.C. This distance that the moon travels in the final 24 hours is 46.5 minutes of declination and is termed
K
by astronomers. It is
a necessary element in the sophisticated mathematical procedure employed
at a Megalithic Lunar Observatory to finally establish the time of the
standstill.
Using the methods of angular displacement,then K,
a measurement of the movement of the Moon in the sky, in arc minutes, can also be referred to as a step- aside distance, in yards, upon the ground adjacent to the backsight stone
S1. This movement when translated to the ground is then termed 4G, (yards, metres or Megalithic Yards). If the distance to
Drygarn Fawr
is known, in miles, then the amount of yards an observer must step
to one side in order to bring the Moon down on the same foresight one day
later, ie. the Major Standstill, can readily be calculated. The distance from S1 to Drygarn cairns is 17.7 mls, (29.5 km), hence 4G
for this site should measure about 1000yds, (923m), and
be situated to the right, (north), of this alignment.
A search of the likely area where a stone might have stood marking
the stance for the true standstill alignment has been made and a small
standing stone pillar with quartz veining discovered at a distance of 880 metres. Photographs of
the Sun setting near the winter solstice have been secured from this stone
and computer extrapolation shows that the Moon's upper limb may settle in the same notch on Drygarn Fawr as seen from S1 but 24 hours apart. This may be the true
Southern Major Lunar Standstill backsight marker as predicted by calculation. Closer estimations of the declination of this alignment will be made when photographs are secured of the Moon setting near the cairn during the period near the next lunar standstill in 2006 AD.
This small standing stone, S3, Llananno is not a recognised antiquity and therefore not protected.
S3, Llananno to Drygarn Fawr west cairn.
Moonset with declination -(e+i)
W/7.6.4 This image is a simulation of the Southern Major Lunar Standstill moonset about 1800 B.C. as viewed over stone S3, Llananno. It has been derived from an image edited survey of two sets of photographs taken of the Sun setting in early January 1999 and at the winter solstice 2001. From a photograph of Sun or Moon crossing the horizon surveys may be made as the astronomical almanacs give the declinations of these bodies for any hour and their apparent diameters. From these two figures the declinations of other points on the horizon may be calculated.
Horizon survey from photographs taken at sunset 11th. Jan. 1999 from S3, Llananno.
W/7.6.6 The cairns of Drygarn Fawr are at an altitude of 1923ft, (641m), on the highest top of the Cambrian Mountain range running north/ south down thespine of Wales. Two ancient, long distance routes cross these mountains to either side of Drygarn Fawr. Today, because of heavy peat growth, it is hazardous for walkers to stray from these vestigial trackways, but in Bronze Age Wales with adrier climate most of this upland would have afforded good grazing pastures. Due to their remote position these cairns are not ordinarily visible from the surrounding territory except to travellers using the cross mountain roads. To find such heavy structures in this isolated terrain is impressive today and must have evoked considerable respect in megalithic times from people moving across this natural divide.
&(e+i-p).jpg)
with comments or queries- powys@megalithicsites.co.uk