The exact instants of equinoxes or solstices are the times when the apparent ecliptic longitude (including the effects of aberration and nutation) of the Sun is 0°, 90°, 180°, or 270°.
ecliptic |
Wasat is only two-tenths of a degree south of the ecliptic, and therefore is occasionally occulted by the Moon and, more rarely, by a planet.
Le Monnier further used the gnomon from 1744 to establish the variations of the ecliptic, or the variations in the obliquity of the Earth's axis.
During the Renaissance, the work was attributed to the Roman historian Gaius Julius Hyginus who lived during the 1st century BC However, the fact that the book lists most of the constellations north of the ecliptic in the same order as Ptolemy's Almagest (written in the 2nd century AD) has led many to believe that a more recent Hyginus created the text.
Of the brightest stars in the sky, Regulus is closest to the ecliptic, and is regularly occulted by the Moon.
"(To the King): Oh Ravivarmadeva, now deign to tell us quickly, reading off from the armillary sphere installed (at the observatory) in Mahodayapura, duly fitted with all the relevant circles and with the sign (-degree-minute) markings, the time of the rising point of the ecliptic (lagna) when the Sun is at 10° in the Sign of Capricorn, and also when the Sun is at the end of the Sign Libra, which I have noted."
Normally, a sidereal year is considered to be 365.25636 days long, but that only applies to stars on the ecliptic, or the apparent path of the Sun.
In this he introduces a new, speculative astrological theory which includes Ophiuchus to employ 13 zodiac constellations and proposes the replacement of the ascendant with the place of the Moon on the ecliptic.
The society was founded two years in Lilienthal, near Bremen, to organize the compilation of ecliptic star charts, with more than half of the members originated from non-German speaking countries.