Sūrya Siddhānta · Chapter 10 of 14
Chapter 10: The moon's rising and setting, her cusps
15 verses. Each section gives the verses, what they state, and, where they compute, the functions that compute them (in SuryaSiddhantaBurgess.js, each checked by a test citing the verse).
10.1 · computed
the Moon visible or invisible at twelve degrees from the Sun
1. udayāstavidhih prāgvat kartavyah śītagor api/
bhāgair dvādaśabhih paścād dṛśyah prāg yāty adṛśyatām//
Computed by: heliacalLimitheliacal
10.2-5 · computed
how long after sunset she sets (light half) or rises (dark half), by repetition
2. ravīndvoh ṣaḍbhayutayoh prāgval lagnāntarāsavah/
ekarāśau ravīndvoś ca kāryā vivaraliptikāh//
3. tannāḍikāhate bhuktī ravīndvoh ṣaṣṭibhājite/
tatphalānvitayor bhūyah kartavyā vivarāsavah//
4. evaṃ yāvat sthirībhūtā ravīndvor antarāsavah/
taih prāṇair astametīnduh śukle +arkāstamayāt param//
5. bhagaṇārdhaṃ raver dattvā kāryās tadvivarāsavah/
taih prāṇaih kṛṣṇapakṣe tu śītāṃśur udayaṃ vrajet//
Computed by: moonAfterSunset
10.6-9 · computed
base and hypotenuse for the cusps; the illuminated part
6. arkendvoh krāntiviśleṣo dikṣāmye yutir anyathā/
tajjyendur arkād yatrāsau vijñeyā dakṣiṇottarā//
7. madhyāhnenduprabhākarṇasaṅguṇā yadi sottarā/
tadārkaghnākṣajīvāyāṃ śodhyā yojyā ca dakṣiṇā//
8. śeṣaṃ lambajyayā bhaktaṃ labdho bāhuh svadiṅmukhah/
koṭih śaṅkus tayor vargayuter mūlaṃ śrutir bhavet//
9. sūryonaśītagor liptāh śuklaṃ navaśatoddhṛtāh/
candrabimbāṅgulābhyastaṃ hṛtaṃ dvādaśabhih sphuṭam//
Computed by: moonCusps
10.10-15 · computed
the figure of the Moon and the elevated cusp; the dark half
10. dattvārkasaṃjñitaṃ binduṃ tato bāhuṃ svadiṅmukham/
tatah paścān mukhī koṭiṃ karṇaṃ koṭyagramadhyagam//
11. koṭikarṇayutād bindor bimbaṃ tātkālikaṃ likhet/
karṇasūtreṇa dikṣiddhiṃ prathamaṃ parikalpayet//
12. śuklaṃ karṇena tadbimbayogād antarmukhaṃ nayet/
śuklāgrayāmyottarayor madhye matsyau prasādhayet//
13. tanmadkhyasūtrasaṃyogād bindutrispṛg likhed dhanuh//
prāgbimbaṃ yādṛg eva syāt tādṛk tatra dine śaśī//
14. koṭyā dik sādhanāt tiryakṣūtrānte śṛṅgam unnatam/
darśayed unnatāṃ koṭiṃ kṛtvā candrasya sākṛtih//
15. kṛṣṇe ṣaḍbhayutaṃ sūryaṃ viśodhyendos tathāsitam/
dadyād vāmaṃ bhujaṃ tatra paścimaṃ maṇḍalaṃ vidhoh// [pāta]
Computed by: moonFigure
Sanskrit: Michio Yano's e-text, GRETIL, SUB Göttingen (version 2020-07-31) (source); editions: B: Hall, Bibliotheca Indica 79, Calcutta 1854; C: Kāśī Saṃskṛta Granthamālā 144, 4th ed. 1987; D: with Sudhākara Dvivedī's commentary, 1987. Variants in ( ) after a word marked *. Licence: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0); shared here unaltered except for layout and one correction: The e-text labels the second half of II.34 "3.34b"; it is placed under II.34 here.Chapter titles, verse numbers and the ledger follow E. Burgess, Translation of the Sûrya-Siddhânta (JAOS 6, 1860).