Nakshatra Baby Name Letter Finder (Birth Star)

In Sinhala Buddhist and Tamil Hindu tradition a newborn's name should begin with a syllable fixed by the janma nakshatra — the lunar mansion the Moon occupied at the moment of birth — and its quarter, the pada. This tool does that lookup from first principles instead of a printed table, so the working is transparent and reproducible.

1. Convert to Julian Day. Your date and time are treated as Sri Lanka local time (a fixed UTC+5:30, no daylight saving), shifted to Universal Time, then converted to a Julian Day using the standard Meeus formula. A small ΔT correction turns UT into the Dynamical Time the lunar theory expects.
2. Compute the Moon's tropical longitude.The Moon's apparent geocentric ecliptic longitude is summed from the periodic series of Jean Meeus, Astronomical Algorithms(Chapter 47). The implemented series is accurate to better than 0.01° — checked against Meeus's own worked example, which lands on 133.167°.
3. Shift to the sidereal zodiac. South Asian astrology uses the sidereal (star-fixed) zodiac, so the Lahiri / Chitra-paksha ayanamsa is subtracted: λ_sidereal = λ_tropical − ayanamsa. The ayanamsa is 24.1128° at the start of 2026 and grows about 50.29 arc-seconds each year.
4. Find the nakshatra and pada. The 360° zodiac splits into 27 nakshatras of 13°20′; each nakshatra into four padas of 3°20′. The nakshatra index is floor(λ_sidereal / 13.3333) and the pada is floor((λ_sidereal mod 13.3333) / 3.3333) + 1.
5. Look up the syllable.The classical Nakshatra-Pada Swar Siddhanta assigns a fixed starting syllable to each of the 108 padas. The tool returns the syllable for the birth pada plus the star's other three, with indicative Sinhala and Tamil forms.

Two independent formulas resolve the same longitude — the nakshatra-first split above, and a global pada index (floor(λ / 3.3333) across the whole circle) — and they must agree, an internal check shown in the tool. Where the Moon sits within roughly ten minutes of a pada edge, the tool warns that the letter can flip if the recorded birth time is slightly off. Only a geocentric Moon position is used; the sub-1° parallax is immaterial next to the 3°20′ pada width.

• DrikPanchang — Nakshatra Pada Swar Siddhanta (108-pada naming-syllable table)
• List of Nakshatras — 27 lunar mansions and their spans
• Ayanamsa — Lahiri / Chitra-paksha definition and drift rate
• NASA GSFC — Espenak & Meeus ΔT (TD − UT) polynomial expressions

The Moon-longitude series follows Jean Meeus, Astronomical Algorithms (2nd ed., 1998), Chapter 47, verified against its Example 47.a. The pada syllable table and the ayanamsa epoch value were last cross-checked on 2026-07-01. Sinhala and Tamil transliterations are indicative and not a substitute for a family almanac reading.