Astroज्योतिष

Today's teaching

“Wealth is the star for wealth; what will the stars do?”
— Kautilya, Arthashastra IX.4

Library · Teachers · The Surya Siddhanta (anonymous; revealed, says the text, by the Sun to Maya) · a 'Saura' text known by the 6th century; the present text revised later

The Surya Siddhanta

The most famous Indian astronomical text, chapter by chapter in plain English from Burgess's 1860 translation: its story, its ages of time, the revolutions of the planets, true positions and the panchanga, the gnomon and precession, eclipses, conjunctions and the stars, heliacal risings, the malignant yogas, its cosmology, its instruments and its nine measures of time. 8 chapters, 7,929 words.

  1. The text and its storyWhat the Surya Siddhanta is, the story it tells of its own origin (the Sun's revelation to the asura Maya), how it relates to the 'Saura' siddhanta Varahamihira knew, Burgess's 1860 translation used here, and the plan of its fourteen chapters.681 words
  2. Time and the agesSurya Siddhanta I.10–24 and XIV: the two kinds of time, the units from the breath to the year, the four ages in the ratio 4:3:2:1, the great age, the age of Manu and the day of Brahma, how much of it has passed, and the nine measures of time and what each is used for.918 words
  3. The revolutions of the planetsSurya Siddhanta I.25–70: why the planets seem to move east, the revolutions of each planet, apsis and node in a great age, the count of months and days that follows, the prime meridian through Ujjain, the size of the Earth, finding longitude from eclipses, and how accurate the numbers are.1,104 words
  4. True places and the panchangaSurya Siddhanta II: why the planets move unevenly (the 'forms of Time' that pull them), the eight kinds of motion, the sine table, the tilt of the ecliptic, the epicycles and the two corrections that turn a mean planet into a true one, retrograde motion, the length of day and night, and the computation of the nakshatra, yoga, tithi and karana.1,021 words
  5. The gnomon, precession and the ascendantSurya Siddhanta III: drawing the cardinal directions with a gnomon and a circle, the shadow triangle, the precession of the equinoxes as a swinging back and forth corrected by observation, finding latitude from the noon shadow, the rising times of the signs at the equator and elsewhere, and how to find the ascendant — the foundation of every chart.1,146 words
  6. EclipsesSurya Siddhanta IV–VI: the sizes of the Sun and Moon and the Earth's shadow, when an eclipse can happen, the physical cause, how much is covered and for how long, the moments of contact, parallax in a solar eclipse, how to draw an eclipse, the smallest eclipse that can be seen, and the colours of the eclipsed Moon.946 words
  7. Conjunctions, stars and risingsSurya Siddhanta VII–X: when two planets meet and how a planetary war is judged, the positions of the junction stars of the nakshatras and the famous 'splitting of Rohini's wain', the distances from the Sun at which planets and stars disappear and reappear, and how to draw the Moon's crescent with its tilted horns.880 words
  8. The malignant aspects, the world and the instrumentsSurya Siddhanta XI–XIII: the 'malignant aspects' of the Sun and Moon (Vyatipata and Vaidhriti) and the knots between the nakshatras; Maya's questions and the answer — the egg of Brahma, the round Earth in space with no top or bottom, Meru and the four cities, day and night in every latitude, the orbits of the planets in yojanas; and the armillary sphere and the water clock.1,233 words

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