Sunsets and solar diameter measurement
Instrumentation and Methods for Astrophysics
2015-05-28 v1
Abstract
A sunset over the sea surface offers the possibility to chronometrate a solar transit across the horizon. The vertical solar diameter is proportional to the duration of the sunset, the cosine of the azimuth and the cosine of the latitude of the observing site. The same formula applies to every circle of equal height, called in arabic almucantarat, and it is exploited in the measurements of the solar diameter made with the Danjon's solar astrolabes. The analogies between sunsets and astrolabes observations are presented, showing advantages and sources of errors of these methods of solar astrometry.
Keywords
Cite
@article{arxiv.1106.2201,
title = {Sunsets and solar diameter measurement},
author = {Costantino Sigismondi},
journal= {arXiv preprint arXiv:1106.2201},
year = {2015}
}
Comments
8 pages, 3 figures, Proc. of 2nd Galileo-Xu Guangqi Meeting, Ventimiglia - Villa Hanbury, Italy, 11-16 July 2010