In astrology, a horoscope is a chart or diagram representing the positions of the Sun, Moon, planets, the astrological aspects, and sensitive angles at the time of an event, such as the moment of a person's birth. The word horoscope is derived from Greek words meaning "a look at the hours" (horoskopos, pl. horoskopoi, or "marker(s) of the hour.") Other commonly used names for the horoscope in English include astrological chart, astro-chart, celestial map, sky-map, star-chart, cosmogram, vitasphere, radical chart, radix, chart wheel, or simply chart. It is used as a method of divination regarding events relating to the point in time it represents and forms the basis of the horoscopic traditions of astrology.

In common usage, horoscope often refers to an astrologer's interpretation, usually through a system of Sun sign astrology or based on calendar significance of an event, as in Chinese astrology. In particular, many newspapers and magazines carry predictive columns based on celestial influences in relation to the zodiacal placement of the Sun on the day of a person's birth, identifying the individual's Sun sign or "star sign." This system is distinct from horoscopes as traditionally employed, as only the zodiacal placement of the Sun is considered in interpretation. While this modern usage is perhaps the most popular in the colloquial lexicon, this article will focus primarily on the traditional concept.

Introduction

Etymology

The word Latin horoscopus, ultimately from Greek lang: ὡρόσκοπος "nativity, horoscope", literally "observer of the hour birth", from lang: ὥρα "time, hour" and lang: σκόπος "observer, watcher". In Middle English texts from the 11th century, the word appears in the Latin form, and is anglicized to horoscope in Early Modern English. The noun horoscopy for "casting of horoscopes" has been in use since the 17th century (OED). In Greek, lang: ὡρόσκοπος in the sense of "ascendant" and lang: ὡροσκοπία "observation of the ascendant" is in use since Ptolemy (Tetrabiblos 33, 75).

Concepts in Western Astrology

main: Western astrology

• The native is the time and place of the event (a birth, for example) being charted, and is considered to be at the centre of the celestial sphere.
• The celestial sphere is a sphere of arbitrary radius upon which the items appearing on the regard to their distance from the native.
• The plane of the equator is the plane of the earth's equator projected into space.
• The plane of the ecliptic is defined by the orbits of the earth and the sun. For practical purposes the plane of the equator and the plane of the ecliptic maintain a constant inclination to each other of approximately 23.5°.
• The plane of the horizon is centred on the native, and is tangential to the earth at that point. In a sphere whose radius is infinitely large, this plane may be treated as nearly equivalent to the parallel plane with its centre at the earth's center. This greatly simplifies the geometry of the horoscope, but does not take into account that the native is in motion. Some writers on astrology have thus considered the effects of parallax, but most would agree that (apart from that of the moon) they are relatively minor Fact: date=February 2008.