Jyotiṣa in the Viṣṇu Dharmottara Purāṇa

Jyotiṣa is the traditional Indian science of the jyotis, the “lights” of the sky: the Sun, the Moon, the planets and the stars. It covers both astronomy (working out where the celestial bodies are) and astrology (reading what their positions mean for life on earth). In the Viṣṇu Dharmottara Purāṇa, a large Purāṇa full of practical teaching, Chapters 166 to 174 of the second part (Dvitīya Khaṇḍa) are given to this science.

In these chapters Bhagavān Brahmā teaches Bhṛgu Ṛṣi the whole science of the lights. The teaching covers the seven kinds of jyotiṣa texts, the twelve rāśis (signs of the zodiac) and their qualities, which planet rules each month of pregnancy, instruments and units of measurement, the kākṣyā measures of planetary orbits, shadow reckoning with a gnomon of 12 aṅgulas, the dhruvakas (reference stars) of the nakṣatras, how the planets move, how to find the tithi from the exact (sphuṭa) positions of the grahas, how to find the equinoxes, how to find the lagna (rising sign) using prāṇa units, the first and last sightings of the planets near the Sun, and the Paitāmaha Siddhānta, Brahmā’s own system of astronomy.

Brahmā Teaching Bhṛgu

Most of the Viṣṇu Dharmottara Purāṇa is told by Puṣkara to Paraśurāma. Some sections have their own inner story, such as the teaching of Garga to Atri. The jyotiṣa section has a different inner story again. When Puṣkara reaches the topic of astronomy, he tells what Bhagavān Brahmā himself taught to Bhṛgu Ṛṣi. Because it comes straight from Brahmā, the Paitāmaha Siddhānta (Brahmā’s own system) is treated as the true foundation for every jyotiṣa calculation in this Purāṇa.

This follows a pattern seen all through the Viṣṇu Dharmottara Purāṇa. Each field of knowledge has its own divine teacher: Gargācārya for the science of omens, Brahmā for astronomy, Paraśara for the mantras of weapons. Knowledge here is never just a technique. It is always wisdom received from a divine source and handed down through a particular line of teachers.

Seven Kinds of Jyotiṣa Texts

Brahmā first sets out the seven kinds of jyotiṣa writing. Together they make up the complete science:

1. Siddhānta: the basic astronomy texts. They lay down the mathematics: how the planets move, how long their orbits take, tables for calculation, and the basic model of the universe. The Paitāmaha Siddhānta is the main one used in the Viṣṇu Dharmottara Purāṇa.
2. Saṃhitā: applied astronomy and astrology. It reads signs in the sky, such as comets, eclipses and unusual planetary positions, as signs of events on earth. Varāhamihira’s Bṛhatsaṃhitā is the classic example.
3. Horā (birth astrology): the study of a person’s birth chart from the positions of the planets at the moment of birth. The system of 12 rāśis, the meanings of the houses, and the daśā-bhukti systems of planetary periods belong here.
4. Gaṇita: the calculation side. It gives the methods and tables needed to work out the exact positions of the planets (sphuṭa-grahas), the tithis, the nakṣatras and the yogas from first principles.
5. Praśna (question astrology): the reading of a chart drawn up for the moment a question is asked, to answer an urgent practical question. It is used a great deal in matters of war (Chapters 162–165 and 175).
6. Jātaka: writings on reading birth charts in detail, including a person’s character, the events of life, and when they will happen according to planetary periods.
7. Muhūrta: the choosing of good times for particular actions, based on the planets, nakṣatras, tithis and yogas. The Viṣṇu Dharmottara Purāṇa uses it again and again to time rituals, military campaigns and ceremonies.

The Twelve Rāśis

Brahmā lists the twelve rāśis (signs of the zodiac) and their qualities:

The three natures, cara (moving), sthira (fixed) and dvisvabhāva (dual or changeable), together with the four elements, are the basis of all work with the rāśis in horā and muhūrta.

Which Planet Rules Each Month of Pregnancy

Earlier, in Chapter 114, the Viṣṇu Dharmottara Purāṇa teaches about garbha-saṃkrānti, the growth of the child in the womb. The jyotiṣa section links back to that teaching by naming the planet that rules each month of pregnancy. The ruling planet shapes the growth that happens in that month:

• Month 1: Candra (the Moon). Life begins, still without form and fluid. Candra rules this watery, unformed stage.
• Month 2: Maṅgala (Mars). The first form becomes firm. Mars gives substance and shape.
• Month 3: Guru (Jupiter). The limbs form. Jupiter’s nature of growth and spreading gives the body its limbs.
• Month 4: Sūrya (the Sun). Bones and skin develop. The Sun’s fiery nature hardens and defines.
• Month 5: Śukra (Venus). Feeling and the sense of beauty develop. Venus rules the senses.
• Month 6: Śani (Saturn). Intelligence and memory develop. Saturn’s drawing-together nature gathers awareness.
• Month 7: Budha (Mercury). Full awareness comes, with memory of past lives; the jīva (the living soul) is most aware at this point. Mercury rules memory and communication.
• Month 8: No clear ruler. This is the critical month of change, and birth in this month is thought unlucky.
• Month 9: All the planets together. The jīva is ready to be born. The planet ruling the moment of birth becomes the lord of the lagna and shapes the person’s janmapatrikā (birth chart).

Causes of miscarriage: The Purāṇa also names planetary patterns, in the mother’s birth chart or in the current movement of the planets, that make garbhapāta (miscarriage) more likely. These include certain combinations of Śani and Maṅgala, certain movements of Rāhu, and an eclipse falling in a critical month.

Instruments and Measurement

The Viṣṇu Dharmottara Purāṇa describes the tools used to observe the sky.

Measuring shadows with a gnomon: The standard gnomon (śaṅku), an upright stick, is 12 aṅgulas (finger-widths) tall. Measuring its shadow lets the astronomer:

• find how high the Sun is at any time of day
• find the equinoxes (when the shadow at noon equals the length of the gnomon)
• keep time through the day

The shadow calculations follow set tables. At different latitudes and seasons, the shadow lengths at noon, morning and evening follow patterns that can be predicted, so the astronomer can find the exact time and the position of the Sun.

Finding the equinoxes: The Purāṇa gives the method for finding the spring and autumn equinoxes from shadow measurements. The equinoxes are key reference points in the yearly calendar. They mark the change between uttarāyaṇa (the Sun’s northward course) and dakṣiṇāyana (its southward course).

Kākṣyā measures: The kākṣyā system measures how far each planet’s orbit is from the earth. The Purāṇa gives relative kākṣyā values that set out the traditional order of orbits around the earth: the Moon (closest), Mercury, Venus, the Sun, Mars, Jupiter and Saturn (the farthest of the visible planets). These measures are used to work out the speeds of the planets and how much weight each planet carries in astrology.

Reference Stars and the Movement of the Planets

Nakṣatra dhruvakas: The Purāṇa gives a reference star (dhruvaka) for each of the 27 nakṣatras (lunar mansions, the star groups the Moon passes through). These are stars that can be picked out in the sky, and they fix where each nakṣatra lies. With them, the astronomer can see which nakṣatra the Moon is in on any night.

How the planets move: The Purāṇa sees the movement of the planets both as something that can be observed and as something sacred. Each planet moves through its cycle by divine will. The planets are not just physical objects. They are conscious beings, the graha-devatās, and their movements show divine intention. The task of the jyotiṣa expert is to read this intention correctly.

Finding the tithi from exact planetary positions: To find the exact tithi (lunar day), one works out the exact angle between the Moon (sphuṭa Candra) and the Sun (sphuṭa Sūrya). Every 12 degrees of separation between the Moon and the Sun makes one tithi. The Purāṇa gives the method for this, using the planetary longitudes worked out from the tables of the Paitāmaha Siddhānta.

Finding the Lagna with Prāṇa Units

The lagna (ascendant) is the point of the zodiac rising on the eastern horizon at a given moment. It is found by counting the prāṇas (units of time of about 4 seconds each) that have passed since the last sunrise. The Purāṇa gives:

• how many prāṇas each rāśi takes to rise at a given latitude (the rising-time values)
• the method for turning the time passed since sunrise into the present lagna
• tables for adjusting to different latitudes

With this, the jyotiṣa-ācārya (teacher of jyotiṣa) can find the lagna for any moment. This matters both for birth charts, where the birth lagna shapes the whole chart, and for praśna-lagna, the lagna of the moment a question is asked.

First and Last Sightings of the Planets

The udaya (heliacal rising) and asta (heliacal setting) of a planet are its first and last appearances in the sky near the Sun. They are important in the Purāṇa’s system:

• When a planet is combust (too close to the Sun), its astrological power is thought to be weakened.
• The first sighting of a planet after it has been hidden is its “rebirth” into full activity.
• The Purāṇa gives, for each planet, the number of degrees from the Sun within which it is counted as asta (set).
• The rising of certain planets in certain seasons is tied to the timing of farming, medicine and ritual throughout the Purāṇa’s calendar.

The most important of these is the rising of Agastya (the star Canopus). The Sāṃvatsarika chapter (Chapter 152) treats it as the sign that the season for military campaigns has opened.

The Paitāmaha Siddhānta

The Paitāmaha Siddhānta, Brahmā’s own system of astronomy, is presented as the base text for all the calculations in Chapters 166–174. “Paitāmaha” means “belonging to the grandfather”. Brahmā is the pitāmaha, the grandfather of all beings.

The Paitāmaha Siddhānta belongs to the Vedāṅga Jyotiṣa tradition. It is one of the five ancient Siddhāntas that Varāhamihira summed up in his Pañcasiddhāntikā. Its main features are:

• its mathematics is fairly simple compared with the later Āryabhaṭīya or Sūrya Siddhānta
• it uses the yuga system (great cycles of years) to work out the average motion of the planets
• it stresses the sacred and universal meaning of events in the sky alongside the mathematics

In the Viṣṇu Dharmottara Purāṇa, the Paitāmaha Siddhānta is not just one system among many. It is the system Bhṛgu received straight from Brahmā. That makes it the most trusted basis for the jyotiṣa calculations behind all the timing of rituals and military actions taught in the Purāṇa.

Sources

• Viṣṇu Dharmottara Purāṇa, Uttarārdha (Dvitīya Khaṇḍa), Chapters 166–174
• Viṣṇu Dharmottara Purāṇa, Part 5