Clive Ruggles - Basic declination calculator

Cultural astronomy

Archaeoastronomy is the study of beliefs and practices relating to the sky in the past, especially in prehistory, and the uses to which people’s knowledge of the skies was put.

Journals, present and past

Cultural astronomy is the combination of archaeoastronomy and ethnoastronomy, which relates to contemporary cultures.

Professional bodies

The 3-volume Springer Handbook contains 217 chapters on themes, issues, methods and practice, and case studies by authors from around the world.

You might also be interested in some of the materials to be found on cultural-astronomy.com.

Basic declination calculator

This calculator uses the same formulae as “GETDEC”, the program referred to in Astronomy in Prehistoric Britain and Ireland (p. 169) and in various publications by myself and others.

The original program is no longer accessible.

Notes

Except in discussing putative high-precision lunar phenomena, the apparent declination is sufficient for all archaeoastronomical purposes. While the program quotes results to arc-second precision, a precision of 0.1 degrees (6 arc minutes) is quite sufficient in most contexts.

The program applies a mean refraction correction to the observed altitude and (for geocentric lunar declinations) mean lunar parallax.

See the Astronomy boxes in Astronomy in Prehistoric Britain and Ireland for more information.

Astronomical heritage

The UNESCO–IAU Portal to the Heritage of Astronomy contains a wide range of examples of different types of astronomical heritage together with information relevant to its protection, conservation, evaluation, management and promotion.