Cove & Pit-Arc Sunrise Alignments in 2018
|Quarter Day 1 (Imbolc)||February 3rd||08:06||8:06 am||119.2||B|
|Semiquarter Day 1||February 25th||07:17||7:17 am||105.3||C|
|Spring Equinox||March 20th||06:18||6:18 am||89.3||D|
|Semiquarter Day 2||April 12th||05:18||6:18 am||73.3||E|
|Quarter Day 2 (Bealltainn)||May 5th||04:23||5:23 am||58.8||F|
|Summer Solstice||June 21st||03:29||4:29 am||43.2||G|
|Quarter Day 3 (Lùnasdal)||August 7th||04:30||5:30 am||58.2||F|
|Semiquarter Day 3||August 30th||05:15||6:15 am||72.5||E|
|Autumn Equinox||September 23rd||06:02||7:02 am||89.0||D|
|Semiquarter Day 4||October 15th||06:46||7:46 am||104.2||C|
|Today||October 16th||06:48||7:48 am||104.9||C|
|Quarter Day 4 (Samhuinn)||November 6th||07:32||7:32 am||118.1||B|
|Winter Solstice||December 21st||08:44||8:44 am||133.6||A|
In his excavation report on Cairnpapple, Stuart Piggott identified the site’s earliest Neolithic structures as: (1) an “irregular arc” of 7 stone-holes (A–G) cut into the basalt bedrock and (B–G) containing traces of cremation deposits; (2) an east-facing “cove” of 3 further stone-holes (PSAS 82 68–123). Piggott himself did not directly connect these two structures, nor did he suggest any calendrical function for them. However, such seems compelling when we map onto his excavation plan the sunrise azimuths for solstices (pits A & G), equinoxes (pit D) and quarter-days (pits B & F), with 4 additional dates apparently indicated exactly halfway between equinoxes and quarter-days (pits C & E) which I’m provisionally calling “semiquarter days” until I can think of something better. Whence this webpage, under development (particularly its maths) towards being a dynamically-programmed representation of Cairnpapple’s “Neolithic Solar Calendar”. If you’ve got any useful feedback, I’d be glad to hear from you.
Astronomical data calculated using NASA’s JPL HORIZONS ephemeris tool. Times & azimuths are topocentric refracted estimates for the centre of the solar disk on (currently) a notionally level horizon.
View maps at OS Magic or Google. Visit the non-virtual Cairnpapple with Historic Scotland. Consult the local weather oracle at the Met Office. Find illumination in Llyfr Aneirin at The National Library of Wales.