🌟 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
- 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.
- Uparāgakriyākrama —
- Four-chapter treatise specifically on solar and lunar eclipses.
- Completed in 1593, placing it firmly in the late 16th century.
- Sphuṭanirṇaya —
- Six chapters, focuses on astronomical calculations.
- 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.
- Chāyāṣṭaka —
- Eight concise verses on astronomical phenomena.
- Uparāgaviṃśati —
- Twenty-verse manual on eclipses, with Malayalam commentary.
- Veṇvārohavyākhyā —
- Commentary in Malayalam on Veṇvāroha by Mādhava of Sañgamāgrama, dealing with tithis and nakṣatras.
On Sanskrit Grammar
- 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
- 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.