Guru

Guru, Jupiter, is the fifth graha and the great benefic of the system, also called Brihaspati after the priest-teacher of the gods, who is its presiding deity. Its gemstone is yellow sapphire, its element is ether (akasha), and its Vimshottari period is sixteen years. In jyotisha Guru signifies wisdom, dharma, teachers, children, wealth, and grace, it is the planet of expansion and blessing, and its favourable aspect is held to protect whatever it touches. Guru rules two signs, Dhanu (Sagittarius) and Meena (Pisces), and is exalted in Karka (Cancer). Because it is the natural significator of fortune and righteousness, its condition is weighed heavily for questions of guidance, prosperity, and religious life. These are the traditional significations of jyotisha; the underlying body is the largest planet, whose slow twelve-year circuit through the signs the tradition tracks.

The name graha comes from the Sanskrit root grah-, to seize or grasp, defining the class by its grip on a nativity rather than by physical status, a definition that lets Rahu and Ketu, mere calculated points, stand alongside a body as substantial as Guru within the same ninefold scheme. Jupiter's place among the classical seven reached Sanskrit astrology from Greek horoscopy through the Yavanajataka, a versification of a Greek astrological text of roughly the second to fourth centuries CE, which brought the machinery of dignity and exaltation to bodies India had already observed for millennia in its own tradition. The wisdom and grace significations attached to Guru, together with his sixteen-year Vimshottari period, belong to a later layer, codified in compilations such as the Brihat Parashara Hora Shastra, generally dated to roughly the seventh or eighth century CE.

Sources Brihat Parashara Hora ShastraSage Parashara (attributed) with Jyotihsastra: Astral and Mathematical LiteratureDavid Pingree, The Yavanajataka of SphujidhvajaDavid Pingree

A graha is not read in isolation but through the several tables that make up a Panchanga and a chart. It rules Thursday in the seven-day week, which in the Indian tradition as in the European one is named for the seven visible grahas in the order of the planetary hours. It holds 16 years of the Vimshottari dasha cycle, and it is lord of three of the twenty-seven nakshatras, Punarvasu, Vishakha and Purva Bhadrapada, spaced nine apart so that the nine grahas cover the twenty-seven exactly three times over.

The Vimshottari dasha system divides a notional lifetime of 120 years among the nine grahas in a fixed order, Ketu, Venus, Sun, Moon, Mars, Rahu, Jupiter, Saturn and Mercury, with fixed lengths that sum to exactly 120. Which period a person begins life in is determined by the nakshatra the Moon occupied at birth, and how far through that period, by how far through the nakshatra the Moon had travelled.

In the scheme of dignities it is exalted in Cancer and in its fall in Capricorn, and dignity is what the classical rules for strength are built on, since a graha in its own sign or its exaltation is read as able to act and one in its fall as constrained.

Jupiter is the great benefic of the system and moves through roughly one sign a year, so its transit is the one most often used to characterise a year in popular practice. Its dasha of sixteen years is among the longest, which means that whether it falls within a given life, and at what age, is one of the more consequential facts a chart yields under this method.