Vedic Astrology
What Is Vedic Astrology (Jyotish)? The Ayanamsa and the 27 Nakshatras
Vedic astrology, known as Jyotish ("the science of light"), is a tradition said to be more than 3,000 years old. Like Western astrology, it reads the positions of the planets — but because it anchors the zodiac differently, the same person's sign can come out one sign earlier than in the Western system.
Sidereal versus tropical
Western astrology uses the "tropical" system, which fixes the spring equinox point as 0° Aries. Vedic astrology instead uses the "sidereal" system, anchored to the actual position of the fixed stars.
The Earth's axis slowly wobbles over a roughly 26,000-year cycle (precession), so the equinox point gradually drifts against the background stars. Today, that drift between the equinox point and the actual stellar positions has reached roughly 24°. The correction figure used to account for this gap is called the ayanamsa.
Because the ayanamsa is roughly 24° — almost exactly one sign's width — someone who is a Western Aries will typically come out as Pisces in Vedic astrology: one sign earlier, as a rule of thumb.
The 12 Rashis and their ruling planets
The 12 signs of Vedic astrology are called Rashis: Mesha (Aries), Vrishabha (Taurus), Mithuna (Gemini), Karka (Cancer), Simha (Leo), Kanya (Virgo), Tula (Libra), Vrishchika (Scorpio), Dhanu (Sagittarius), Makara (Capricorn), Kumbha (Aquarius), and Meena (Pisces).
Each Rashi has a ruling planet. Mesha and Vrishchika are ruled by Mars; Vrishabha and Tula by Venus; Mithuna and Kanya by Mercury; Karka by the Moon; Simha by the Sun; Dhanu and Meena by Jupiter; and Makara and Kumbha by Saturn. Vedic astrology doesn't use Uranus, Neptune or Pluto, working instead with the naked-eye planets plus two calculated points, Rahu and Ketu.
The 27 Nakshatras and Tarabala
A particularly important concept in Vedic astrology is the Nakshatra (lunar mansion) — 27 divisions of the celestial sphere running from Ashwini through to Revati. Whichever Nakshatra the Moon occupied at your birth becomes your birth Nakshatra.
Day-to-day fortune is judged through Tarabala. Taking the distance from your birth Nakshatra to today's Nakshatra, modulo 9, sorts each day into one of nine categories: Janma (Birth), Sampat (Wealth), Vipat (Danger), Kshema (Well-being), Pratyak (Obstacle), Sadhaka (Accomplishment), Vadha (Destruction), Mitra (Friendship), and Ati-Mitra (Best Friend).
Sampat, Sadhaka and Ati-Mitra days favour decisive action, while Vipat and Vadha days call for playing defence. The strong resemblance to Sukuyo astrology is no coincidence — both trace back to the same Indian astronomical roots.
How this site calculates it
Your Rashi is approximated by taking your Western tropical Sun sign and shifting it back one sign to account for the ayanamsa (roughly 23.85°). Your Nakshatra is calculated deterministically on a 27-part cycle from your date of birth.
Your Lagna (rising sign) is approximated from your birth time and the longitude difference between your birthplace and the Indian Standard Time meridian (82.5°E). If your birth time is unknown, your Lagna is treated as identical to your Rashi.
Full Jyotish practice goes on to layer in Dasha (planetary periods), Varga (divisional charts), and much more besides. What this site offers is best understood as an entry point into that much larger system.
Frequently asked questions
Western astrology says I am a Taurus, but Vedic astrology says Aries. Why?
The ayanamsa correction of about 24 degrees shifts the zodiac, so anyone whose Sun sits in the first part of a Western sign moves to the previous sign in the sidereal system. Both are correct within their own conventions.
What is a dasha?
A technique that divides life into planetary periods. The most common, Vimshottari, runs 120 years from the birth nakshatra with periods of Ketu 7, Venus 20, Sun 6, Moon 10, Mars 7, Rahu 18, Jupiter 16, Saturn 19 and Mercury 17 years.
What is the Navamsha?
A divisional chart (D9) made by dividing each sign into nine parts, used to read marriage, later life and inner quality. See the reading screen for what this site displays.
Are Rahu and Ketu real planets?
No. They are the two points where the Moon's orbit crosses the ecliptic, the positions where eclipses occur, and are treated as 'shadow planets' of great importance.
How much can be read without a birth time?
The Moon's sign and nakshatra are fixed for most of a day, so the daily reading and basic character can be given without a time. The Lagna and houses need it.
* This article introduces the ideas behind this divination tradition and makes no claim to scientific validity. Please enjoy your reading as entertainment.