Astrology

Astrology (占星術) is a system involving the use of astrological phenomena, such as the positions of the stars and planets in the night sky, for the purpose of divination.

In Toaru Majutsu no Index, certain forms of Magic make use of astrology.

Etymology
Astrology is derived from the Latin astrologia, in turn derived from the Greek ἀστρολογία, approximately meaning 'study of the stars', comprised of ἄστρον/astron ("star") and -λογία/-logia, ("study/account of"). Astrologia later came to refer to 'star-divination' while astronomia (later Tenmongaku (天文学)) was used for the scientific term.

Principles
There are various patterns formed by the stars in the night sky, and some of these are considered to form images at specific points in the night sky. These are known as constellations (星座). The number of recognized constellations have changed over time and between different locations, with many cultures having various tales associated with them. In modern times, there are eighty-eight officially recognized constellations, many of them derived from Classical Mythology.

Among these are a group of twelve constellations known as the, which follow the ecliptic belt across the celestial sphere which the Sun and planets travel along. The signs of the Zodiac are important elements in astrology, with various attributes associated with them, such as personality types, elements, times of the year and day, entities, and ruling planets.

The planets are another important aspect of astrology, with the ones traditionally used being Mercury (水星) (☿), Venus (金星) (♀︎), Mars (火星) (♂︎), Jupiter (木星) (♃) and Saturn (土星) (♄), together with the two 'lights'; the Sun (太陽) (☉) and the Moon (月) (☽). Like the Zodiac signs, the planets have various qualities associated with them, including entities such as angels and Planetary Spirits (惑星霊).

The positions of the constellations and the planets observed in the night sky and in relation to each other (angles and proximity), combined with their individual qualities, are used to divine for a specific point in time, with different meanings and interpretations arising at different times. These positions and meanings can be used as a basis for various spells, a fair number of which are dependent on the state of celestial sphere.

For astrology, where the stars are actually located in the universe is of little importance compared to how they line up when viewed from Earth - it is the latter from which meanings are derived.

As well as the stars and planets, there are a number of other mysterious lights in the night sky. These have been viewed as unlucky stars and ill omens for millennia, and only within the past few decades been superseded by the idea of and vehicles flown by aliens.

Western Astrology
In Western Astrology, the twelve signs of the Zodiac are Aries (白羊宮) (♈︎), Taurus (金牛宮) (♉︎), Gemini (双児宮) (♊︎), Cancer (巨蟹宮) (♋︎), Leo (獅子宮) (♌︎), Virgo (処女宮) (♍︎), Libra (天秤宮) (♎︎), Scorpio (天蝎宮) (♏︎), Sagittarius (人馬宮) (♐︎), Capricorn (磨羯宮) (♑︎), Aquarius (宝瓶宮) (♒︎) and Pisces (双魚宮) (♓︎). As well as a month-long time period in the year, personality type, and element, they also have one of three modalities:, and.

Astrology of this kind plays an important role in Hermeticism, being said to be one of the three parts of the wisdom of the universe held by Hermes Trismegistus.

Part of Golden-style magic involves the observation and use of the stars and mysterious lights in the night sky. As well as reading the future from the stars, magicians seal their light into talismans and amulets, and draw their power out when they see fit. Karasuma Fran is an example of a magician who practices Golden-style astrological magic. In Golden-style magic, the zodiac signs have a color (e.g. bright red for Aries and yellowish-green for Virgo) and an angel associated with them.

Eastern Astrology
Onmyoudou makes use of certain aspects of astrology.

Indian astrology, also referred to as Vedic and Navagraha Astrology (九曜占星術), tells fortunes through the positions of 9 Navagraha; the Sun, the Moon, Mercury, Venus, Mars, Jupiter, Saturn, Rāfu (ラーフ)(☊) and Kēto~u (ケートゥ) (☋), as well as the angles of the constellations.

Index Arc
John's Pen Index mentioned the location of the stars, angle of the moon, and Cancer while preparing healing magic ritual.

Deep Blood Arc
Index mentioned astrology during her first meeting with Himegami Aisa regarding her validity as a magician. Modern Astrology was included in her list together with the likes of Enoch, Kabbalah, Hermeticism and Vision of Mercury.

Daihasei Festival Arc
Astrology is referred to during the events in the Daihaseisai, with some of the laws behind Oriana Thomson's Shorthand coming from the basis of Western Astrology.

Toaru Majutsu no Index SS: Necessarius Special Admission Test
Astrology is referred to among the various magical-related systems which depend on the positions of the stars in the night sky, which the group known as the Royal Astronomical Research Organization was formed to observe, in order to obtain data regarding the use of those systems.

World War III Arc
During World War III, Fiamma of the Right made use of Archangel Gabriel to clear the heavens and leave the Star of Bethlehem as the only 'star' in the night sky, as part of Project Bethlehem. When Fiamma was using the Star of Bethlehem to correct the Distortion of the Laws of the World and reset the four elements, a series of colored stars spread out across the sky.

Aleister Crowley Arc
During the battle with the Karma chain beasts, Fran invoked Virgo in a spell though the chains' interference caused Aries to activate instead. During the visions in the Windowless Building, it is also described how Aleister Crowley determined his daughter Lilith's long name by reading the stars.

Coronzon Arc
While describing the problems with using Spiritual Tripping against Isis-Demeter when it was using Orsola Aquinas as a host, Aleister mentioned how Spiritual Tripping uses mime and astrological suggestion to bind the user to the target. He later referred to points in astrology when describing the Lady of the Masquerade Ball's use of the Planetary Spirit of Mercury, Taphthartharath.

When Coronzon prepared the Queen Britannia's temple for the Ceremony of Mo Athair, the seven planetary forces and the twelve zodiac influences were among the influences which she banished from the ceremonial ground. During Coronzon's remote attack on the group at Edinburgh Castle, Index referred to how astrology was thrown in chaos by the discovery of new planets (e.g. Uranus) but these objects (e.g. Pluto) do not obstruct the movements of the universe, during her misreading of the Book of the Law aimed at disrupting Coronzon's spell so that Aleister could destroy it.

Christmas Eve Arc
The associations of the seven metals with the planets (and from that the Sephirah) and invented angels with the Zodiac were brought up by Index and Othinus during analysis of the magic which Neoka Norito had acquired from R&C Occultics.

Astrological organizations

 * Astrological Surgery Brigade
 * Royal Astronomical Research Organization
 * Spanish Astrological Sect