Where a method has more than one accepted form, the app exposes the choice — for example, the Shadbala reading school and the ayanāṁśa setting — rather than silently picking one. This means you can always align the output with the text or lineage you follow.
B. V. Raman — Graha and Bhava Balas
This focused manual on the numerical strength of planets and houses is the app’s primary source for the Shadbala system. Specifically, it grounds:- The six balas and their components: Sthāna-bala, Dig-bala, Kāla-bala, Cheṣṭā-bala, Naisargika-bala, and Dṛk-bala.
- The Bhāva-bala calculation (house strength), and the Ishta/Kashta Phalas (benefic and malefic results).
- The minimum virūpa thresholds the app uses to produce a planet’s strength ratio — Sun 300, Moon 360, Mars 300, Mercury 420, Jupiter 390, Venus 330, Saturn 300.
P. V. R. Narasimha Rao — Vedic Astrology: An Integrated Approach
A comprehensive modern textbook with worked examples covering fundamentals through advanced techniques, this is the source that grounds the broadest range of the app’s features:- Fundamentals — rāśis, grahas, bhāvas, karakas, aspects, and yogas, introduced in the Concepts section.
- Divisional charts — the full Shoḍaśavarga and the interpretive principles for each varga (Part 1).
- Ashtakavarga — BAV and SAV construction, reductions, and transit scoring (ch. 12).
- Vimśottarī daśā and other daśā systems, with period-sequencing rules (Part 2).
- Gochara / transits — transit analysis from the Lagna and Moon, combined with Ashtakavarga bindus and nakṣatra triggers (Part 3).
- Tājaka / Varshaphal — annual charts, Tājaka yogas, and annual daśā systems (Part 4).
- Muhūrta and the impact of birth-time error — behind Choosing a date and the birth-time guidance in Troubleshooting (Part 5, ch. 32).
V. P. Jain — Elements of Astronomy (for astrologers)
A lean, technically precise treatment of the astronomy underlying the astrology. It grounds the app’s astronomical engine rather than its interpretive layer:- Sidereal vs. tropical time — the mathematical basis for converting between the two frameworks.
- The ayanāṁśa and the precession of the equinoxes — how and why the sidereal and tropical zodiacs drift apart over centuries. See Ayanāṁśa options.
- Lunar months and tithis — the arithmetic of the luni-solar calendar, behind the Panchāng’s tithi calculations.
- Sunrise, sunset, and ascendant calculation — the spherical trigonometry used to place the Lagna. See The sidereal sky and Panchāng.
Bṛhat Parāśara Horā Śāstra (BPHS)
The foundational classical compendium attributed to the sage Parāśara, and the ultimate textual authority behind the app’s core framework:- Parāśarī aspects — the full-strength and special aspects of each graha used throughout the chart.
- Whole-sign houses — the house system the app uses by default.
- Divisional chart definitions — the canonical method for deriving each of the sixteen vargas.
- Vimśottarī daśā — the period lengths and sequence that the app implements.
Feature-to-source mapping
| Feature | Principal source(s) |
|---|---|
| Sidereal positions, ayanāṁśa, sunrise/sunset | Jain; BPHS |
| Signs, planets, houses, aspects | Rao; BPHS |
| Divisional charts (Shoḍaśavarga) | Rao; BPHS |
| Shadbala (six balas, thresholds, Bhāva-bala) | Raman; BPHS |
| Ashtakavarga (BAV / SAV) | Rao; BPHS |
| Vimśottarī daśā | Rao; BPHS; Jain |
| Gochara (transits) | Rao |
| Tājaka / Varshaphal | Rao |
| Ashtakūṭa compatibility | Classical matchmaking literature; Rao |
| Panchāng (five limbs, muhūrta) | Jain; Rao |