Rohini

Rohini is the fourth nakshatra, from 40 to 53 degrees 20 minutes of the sidereal zodiac, within Taurus, and its star is Aldebaran, the red eye of the Bull. Its Vimshottari ruler is the Moon; its presiding deity is Brahma, called here Prajapati, the creator; and its symbol is an ox-cart or chariot. The Moon is held to be exalted near this point, and Rohini is traditionally the Moon's favourite mansion, a well-known myth tells of the Moon's love for Rohini among the daughters of Daksha. Jyotisha therefore reads it as a mansion of growth, fertility, beauty, and material abundance, classed as Manushya gana. The name means the red or growing one. These are interpretive conventions of the tradition; the underlying star, Aldebaran, is a first-magnitude giant that anciently served as a marker across many cultures.

The pada sequence for Rohini runs through Sagittarius, Capricorn, Aquarius and Pisces, one of the many fixed correspondences that let a jyotishi read a planet's Navamsha placement directly from its exact degree within the nakshatra. Aldebaran itself is not part of the Hyades cluster it appears to sit within, an unrelated foreground star roughly half the distance to Earth that the cluster's stars share, a fact unknown to the ancient compilers but not inconsistent with their treatment of Rohini as a single bright marker rather than a cluster like Krittika. The Daksha myth also explains a persistent minor theme in Rohini's classical delineation, a hint of favouritism and consequent imbalance, since the Moon's excessive devotion to Rohini among Daksha's twenty-seven daughters is the very fault the myth uses to account for the Moon's periodic waning as a curse from the aggrieved father-in-law.

Every nakshatra is quartered. The four padas, literally feet, are the smallest unit jyotisha divides the ecliptic into and the reason the system can say anything finer than thirteen degrees. Rohini runs from 40 degrees 00 minutes to 53 degrees 20 minutes of the sidereal circle, and its four padas are three degrees twenty minutes each: the first from 10 degrees 00 minutes of Taurus, the second from 13 degrees 20 minutes of Taurus, the third from 16 degrees 40 minutes of Taurus and the fourth from 20 degrees 00 minutes of Taurus. The Moon crosses a single pada in roughly six hours, so a birth an afternoon apart can fall in two of them.

The arithmetic hides a coincidence that is not one. Twenty seven nakshatras of four padas make one hundred and eight divisions of the zodiac, and the navamsha, the ninth-part chart that jyotisha treats as the most important of all the divisional charts, also cuts the circle into one hundred and eight. They are the same cut. A pada is a navamsha, and naming the pada names the navamsha sign without any further calculation. The four padas of Rohini fall in Aries, Taurus, Gemini and Cancer in that order.

Two cautions attach to those degrees. They are sidereal, measured from a fixed point among the stars rather than from the equinox, so they depend on the ayanamsha chosen to locate that point; the Lahiri, Raman and Krishnamurti values differ by up to about a degree, which is a fifth of a pada and enough to move a chart across a boundary. And the equal arcs are a scheme laid over the sky rather than a description of it: the star the nakshatra is named for sits somewhere inside its arc rather than filling it, and for several nakshatras that identification is itself disputed.