stone rings, in particular, frequently have alignments to
the rising sun. Locally, Swinside has a portal to the mid-winter
sunrise; Banniside (below Coniston Old Man) has a marker
stone to the north-east for the mid-summer sunrise. Uniquely
at Sunbrick, every sunrise between mid-winter and mid-summer
is visible on a distant horizon; key features on the horizon,
not the positions of the stones, mark the progress of the
sun. Surprisingly, this aspect of the Birkrigg stone rings
seems to have been seriously over-looked in the past. There
is possibly no other stone circle in the country which offers
this facility to view the full annual cycle of sunrise so
clearly on the horizon – it’s like watching
a pendulum swing one way over six months, then back again.
the mid-winter solstice, 21st December, the sun rises around
8.30 a.m., at its most southerly point of the year. When
seen from the Sunbrick stone rings this is behind the Bowland
Fells, just as Hawthornthwaite Fell dips sharply to the
west. For several days the sun appears to be standing still
(hence solstice), rising at the same point each day*.
the sun begins its apparent journey northwards, the position
of the sun's rising moves a little further towards the north
each day. At the mid-point, at the spring and autumn equinoxes
of equal night and day in March and September, sun rise
occurs immediately behind Ingleborough, a very recognisable
outline on the horizon (behind Humphrey Head in the foreground);
it occurs at 6 a.m. (7 a.m. in autumn due to B.S.T.).
at the mid-summer solstice, on 21st June, the sun rises
at its furthest point north; when seen from the stone rings,
this event occurs just beyond the northern end of Chapel
Island in the estuary (at least as it was before it was
denuded by quarrying in Victorian times).
the purist, the movement in the position of the sunrise
occurs because of the earth’s tilt on its axis. The
tilt of the earth’s axis oscillates between 24.5°
and 22° on a 41,000 year cycle and is currently decreasing.
The extremes of northern and southern rising points of the
sun during the year will therefore change slightly over
this cycle, but it is less than ½° (about the
sun’s width) over the 4000 years that the stone rings
may have existed.
also provides the perfect place to observe the moon. Like
sun rise, the position of moon rise changes from north-east
to south-east and back again, but over a period of 29 days
rather than one year.
pattern for the moon is the reverse of that for the sun.
The full moon nearest to the mid-winter solstice rises in
the early evening and at its furthest position north
for that year, while in mid-summer full moon rises late
in the evening, at its furthest position south
for the year.
mid-winter full moon will rise just before the sun sets
about 5 p.m.. On 3rd January 2015, at a minor lunar standstill,
the moon rose just behind the north end of Hampsfell, as
the last of the sun’s rays caught the tops of the
stones in the ring. This was at the northenrmost point for
months later, on 2nd July 2015, the full moon rose at 9.30 p.m.
at its most southern point of the year, behind the Trough of
full moon nearest to the autumn equinox, rising in the vicinity
of Ingleborough, is known as the Harvest moon. In times when
harvests were gathered manually this allowed all night working,
as there were 12 hours of moonlight (clouds permitting). Additionally,
at this time of year the moon rises about 35 minutes later each
day, earlier than the average for the year, so it seems that
the full moon lasts several days, allowing the harvest to be
28th September 2015 the full moon occurred when the moon was
at its closest to the earth in its orbit, a perigee or supermoon.
In addition, at around 4 a.m., there was an eclipse of the moon
creating a blood moon. What our Bronze Age ancestors would have
made of this demonstration by the gods is anybody's guess!
clearly, the choice of site for Birkrigg’s stone rings is
related to its elevated position and the open aspect to the east,
giving a panorama which embraces the northern and southern extremes
of sun rise and moon rise during the year.
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