Nisargayu

Definition

Nisargayu (Naisargika Ayurdaya, "natural life-span") is a longevity method — one way Jyotish estimates how long a life will run. Rather than reading the span from where each planet sits in the chart, it gives every planet a fixed natural quota of years, counted from birth. In the Brihat Parasara Hora Sastra as Santhanam translates it, those quotas are the Moon 1, Mars 2, Mercury 9, Venus 20, Jupiter 18, the Sun 20, and Saturn 50 years — each then adjusted by the planet's distance from its exaltation, as in the Pinda method.

In Tradition

The Jyotish sources gathered here — classical and modern — agree on what Nisargayu reckons: each planet contributes a fixed "natural" quota of years from birth, and those raw quotas are scaled by each planet's distance from its exaltation, just as the Pinda method does. They also agree on when it applies: among the several Ayurdaya (longevity) methods, Nisargayu is the one chosen when the Moon is the strongest of the reference points used.

In Practice

A jyotishi reaches for Nisargayu, per Charak, when the Moon is the strongest of the Sun, the Moon, and the lagna (the rising sign) — Pindayu being the method used when the Sun is strongest, and Amshayu when the lagna is strongest. The Jataka Parijata frames the same trigger differently: the Moon being strong and holding a benefic aspect. Once Nisargayu is in play, you take each planet's fixed quota and scale it by the planet's distance from exaltation, as in the Pinda method. Santhanam notes that one recension adds rectifications: the figures hold at deep exaltation, are halved at debilitation, and pass through the same four reductions used in Pindayu. Summed across the planets, the result gives the natural life-span estimate.

Historical Origin

Nisargayu is laid out in the Brihat Parasara Hora Sastra, Chapter 43 (Sl.16-17, 30-31), attributed to Maharshi Parasara and read here through R. Santhanam's translation, where it carries an A-class verbatim quota. As Naisargikayurdaya it appears in Vaidyanatha Dikshita's Jataka Parijata, Chapter 5 (Sl.1, 6, 28), in Sastri's translation. Among modern authors, Charak treats it in Elements of Vedic Astrology as the third mathematical longevity method.

Further Reading

• Maharshi Parasara (trans. Santhanam), Brihat Parasara Hora Sastra Ch.43 Sl.16-17, 30-31
• Vaidyanatha Dikshita (trans. Sastri), Jataka Parijata Ch.5 Sl.1, 6, 27-28
• Charak, Elements of Vedic Astrology Ch.XXIII