Thrikkandiyur Achutha Pisharody

🌟 Thrikkandiyur Achutha Pisharody (1545–1621)

• A brilliant astronomer, grammarian, and Ayurvedic scholar from Kerala during the 16th–17th centuries.
• Preceptor (guru) to Melpathur Narayana Bhattathiri, the celebrated author of Narayaneeyam.
• Contemporary of Thunjath Ezuthachan, the father of the Malayalam language.

📚 His Major Works

On Astronomy & Mathematics

1. Karaṇottama (1593) —
   • Five chapters, ~100 verses.
   • Discusses computation of mean and true longitudes of planets, eclipses, and solar-lunar conjunctions (vyatūpātas).
   • A self-commentary exists.
2. Uparāgakriyākrama —
   • Four-chapter treatise specifically on solar and lunar eclipses.
   • Completed in 1593, placing it firmly in the late 16th century.
3. Sphuṭanirṇaya —
   • Six chapters, focuses on astronomical calculations.
4. Rāśigolasphuṭānūti —
   • 50 verses explaining the reduction of the Moon’s longitude to the ecliptic—a sophisticated step in positional astronomy.
   • References both Sphuṭanirṇaya and Uparāgakriyākrama, proving it was written later than 1593.
5. Chāyāṣṭaka —
   • Eight concise verses on astronomical phenomena.
6. Uparāgaviṃśati —
   • Twenty-verse manual on eclipses, with Malayalam commentary.
7. Veṇvārohavyākhyā —
   • Commentary in Malayalam on Veṇvāroha by Mādhava of Sañgamāgrama, dealing with tithis and nakṣatras.

On Sanskrit Grammar

1. Praveśaka (Pravesakam) —
   • Introductory Sanskrit grammar text (~600 anuṣṭubh stanzas).
   • Written to teach his student Melpathur.
   • Remains an important primer in Kerala’s Sanskrit tradition.

On Astrology

1. Horāsāroccaya —
   • Seven chapters adapting Srūpati’s Jātakapaddhati.
   • Explores horoscopy (jātaka) and predictive techniques.

🔭 Scientific Contributions

• Pisharody’s works include detailed computations for eclipses, planetary motions, and innovations like techniques for the reduction of the ecliptic, which are crucial steps for accurate astronomical predictions.
• His treatises demonstrate a high level of mathematical sophistication and a deep understanding of spherical astronomy.

🏆 Significance

• He is a vital link in Kerala’s rich tradition of mathematical astronomy, which includes luminaries like Mādhava of Sangamagrama.
• His clear expositions and systematic works helped standardize astronomical practices in Kerala for generations.
• His grammatical text Praveśaka continued Kerala’s strong Sanskrit scholarship, bridging astronomy, astrology, and linguistics.

• The exact relationship between this work and the Horātantraṃ Parijbhāṣa, a Malayalam commentary on Jātakapaddhati, remains uncertain.

Further discussion of Acyuta Piṣāraṭi may be found in S. Venkitasubramonia Iyer, “Acyuta Piṣāroṭi; His Date and Works,” in JOR Madras, 22 (1952–1953), 40–46; and K. Kunjunni Raja, The Contribution of Kerala ot Sanskrit Literature (Madras, 1958), pp. 122–125, and “Astronomy and Mathematics in Kerala,” in Brahmavidyā, 27 (1963), 158–162.