An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The shape resembling a figure of 8 obtained by following the Sun's position in the sky at the same time of day throughout the year. It is a graphical presentation of the → equation of time. Because the Earth's orbit around the Sun is elliptical, the two loops of analemma have different sizes. Analemma figures for different latitudes or different times of day would appear slightly different. The analemma is widest in the period when the Earth is closest to the Sun (December). This is because in this situation the Earth advances in its orbit faster due to the stronger gravitational attraction of the Sun. On the other hand, since the Earth rotates at a constant rate, the Sun appears to rise earlier than average because the Earth advances further in its orbit in one day when the Earth is close to the Sun. The opposite occurs in June when the Earth is further from the Sun.

From L. analemma "the pedestal of a sundial," hence the sundial itself, from Gk. analemma "prop, support," from analambanein, from → ana- "up" + lambanein "to take".

Hurspicak from hur "Sun;" Av. hvar- "sun" (cf. Skt. surya; Gk. hlios; L. sol; O.H.G. sunna; Ger. Sonne; E. sun; PIE *sawel- "sun") + picak "a curled, a twisted figure or object," from picidan "to twist, invove, enttwine, coil."