The Texts · The Foundational Six
Sūrya Siddhānta
सूर्यसिद्धान्त
Traditionally revealed by Sūrya to Asura Maya (a frame story, not an author) · Received text c. 800 CE (further revised toward c. 1000); an older core of c. 400 CE is known only through Varāhamihira’s summary · ganita
On the dating: The scholarly consensus is a layered history: an older Sūrya Siddhānta summarized in the 6th-century Pañcasiddhāntikā, a major revision around 800 CE, and the received vulgate close to 1000 CE.
What this text is
The classic treatise of Hindu mathematical astronomy — the text whose definitions the traditional pañcāṅga vocabulary descends from.
Mean and true planetary motions, terrestrial longitude corrections, ascendant and meridian computation, diurnal problems, lunar and solar eclipses with parallax, heliacal risings, the gnomon, cosmography and the yuga time-scale.
Its role in this app
Definitional heritage: our engine computes from modern ephemerides, and this text documents what the tradition’s numbers meant. Cited in the Kali-ahargaṇa epoch decision (midnight epoch, elapsed days) and in our refusal to approximate the North-Indian Bārhaspatya cycle, which would need this text’s expunction tables to compute faithfully.
Editions our research holds
1935-reprint
E. Burgess translation (1860), Calcutta University 1935 reprint — the primary copy.
public domain · scan quality: good
burgess-english-text
Second clean Burgess copy for cross-checking constants.
public domain · scan quality: good
burgess-1860
Burgess 1860, DLI scan — noisier.
public domain · scan quality: usable
sanskrit-hindi-2021
Modern Ram Chandra Pandey Sanskrit-Hindi edition (two copies, in copyright) plus an old public-domain Gudārtha-Prakāśa print (sandhi-run, nearly ungreppable).
in copyright — read for verification only, never republished · scan quality: usable
Readings on this site cite texts at chapter level, with verse numbers only where our research verified the passage in a named edition. How conflicts between texts are resolved is documented on the conventions page.