Chapter 4: Eclipses, especially lunar

4.1-5 · computed

diameters of Sun and Moon, corrected by motion; carried to the moon's orbit; the shadow

1. sārdhāni ṣaṭsahasrāṇi yojanāni vivasvatah/
viṣkambho maṇḍalasyendoh sahāśītyā catuśśatam//

2. sphuṭasvabhuktyā guṇitau madhyabhuktyoddhṛtau sphuṭau/
raveh svabhagaṇābhyastah śaśāṅkabhagaṇoddhṛtah//

3. śaśāṅkakakṣāguṇito bhājito vā +arkakakṣayā/
viṣkambhaś candrakakṣāyāṃ tithyāptā mānaliptikā//

4. sphuṭendubhuktir bhūvyāsaguṇitā madhyayoddhṛtā/
labdhaṃ sūcī mahīvyāsasphuṭārkaśravaṇāntaram//

5. madhyenduvyāsaguṇitaṃ madhyārkavyāsabhājitam/
viśodhya labdhaṃ sūcyāṃ tu tamo liptās tu pūrvavat//

Computed by: eclipseDiametersCONSTANTS.SUN_DIAMETER_YOJANASCONSTANTS.MOON_DIAMETER_YOJANAS

4.6 · descriptive (nothing to compute)

an eclipse when the node is within "a few degrees" of the Sun or the shadow (no limit stated; the test is IV.10-11)

6. bhānor bhārdhe mahīcchāyā tattulye +arkasame +api/
śaśāṅkapāte grahaṇaṃ kiyadbhāgādhikonake//

4.7-8 · computed

the moment of conjunction or opposition, the places made to agree

7. tulyau rāśyādibhih syātām amāvāsyāntakālikau/
sūryendū paurṇamāsyante bhārdhe bhāgādikau samau//

8. gataiṣyaparvanāḍīnāṃ svaphalenonasaṃyutau/
samaliptau bhavetāṃ tau pātas tātkāliko +anyathā//

Computed by: syzygy

4.9 · descriptive (nothing to compute)

the Moon eclipses the Sun; the earth's shadow eclipses the Moon

9. chādako bhāskarasyendur adhahstho ghanavad bhavet/
bhūcchāyāṃ prāṅmukhaś candro viśaty asya bhaved asau//

4.10-11 · computed

amount obscured; total, partial or none

10. tātkālikenduvikṣepaṃ chādyacchādakamānayoh/
yogārdhāt projjhya yaccheṣaṃ tāvac channaṃ tad ucyate//

11. yad grāhyam adhike tasmin sakalaṃ nyūnam anyathā/
yogārdhād adhike na syād vikṣepe grāsasambhavah//

Computed by: lunarEclipse

4.12-17 · computed

half-durations and half-totality, corrected for motion in latitude by repetition; the phases

12. grāhyagrāhakasaṃyogaviyogau dalitau pṛthak/
vikṣepavargahīnābhyāṃ tadvargābhyām ubhe pade//

13. ṣaṣṭhyā saṃguṇya sūryendvor bhuktyantaravibhājite/
syātāṃ sthitivimardārdhe nāḍikādiphale tayoh//

14. sthityardhanāḍikābhyastā gatayah ṣaṣṭhibhājitāh/
liptādi pragrahe śodhyaṃ mokṣe deyaṃ punah punah//

15. tadvikṣepaih sthitidalaṃ vimardārdhe tathā +asakṛt/
saṃsādhyam anyathā pāte talliptādiphalaṃ svakam//

16. sphuṭatithyavasāne tu madhyagrahaṇam ādiśet/
sthityardhanāḍikāhīne grāso mokṣas tu saṃyute//

17. tadvad eva vimardārdhanāḍikāhīnasaṃyute/
nimīlanonmīlanākhye bhavetāṃ sakalagrahe//

Computed by: lunarEclipse

4.18-21 · computed

the amount obscured at a given time

18. iṣṭanāḍīvihīnena sthityardhenārkacandrayoh/
bhuktyantaraṃ samāhanyāt ṣaṣṭyāptāh koṭiliptikāh//

19. bhānor grahe koṭiliptā madhyasthityardhasaṃguṇāh/
sphuṭasthityardhasaṃbhaktāh sphuṭāh koṭikalāh smṛtā//

20. kṣepo bhujas tayor vargayuter mūlaṃ śravas tu tat/
mānayogārdhatah projjhya grāsas tātkāliko bhavet//

21. madhyagrahaṇataś cordhvam iṣṭanāḍīr viśodhayet/
sthityardhān maukṣikāc cheṣaṃ prāgvac ccheṣaṃ tu maukṣike//

Computed by: obscurationAt

4.22-23 · computed

the time of a given amount of obscuration

22. grāhyagrāhakayogārdhāc chodhyāh svacchannaliptikāh/
tādvargāt projjhya tatkālavikṣepasya kṛtiṃ padam//

23. koṭiliptā raveh spaṣṭasthityardhenāhatā hṛtāh/
madhyena liptās tannāḍyah sthitivad grāsanāḍikāh//

Computed by: timeOfObscuration

4.24-25 · computed

deflection (valana) for latitude and for the ecliptic, in digits

24. natajyā +akṣajyayābhyastā trijyāptā tasya kārmukam/
valanāṃśā saumyayāmyāh pūrvāparakapālayoh//

25. rāśitrayayutād grāhyāt krāntyaṃśair dikṣamair yutāh/
bhede +antarāj jyā valanā saptatyaṅgulabhājitā//

Computed by: valana

4.26 · computed

the scale of projection

26. sonnataṃ dinamadhyārdhaṃ dinārdhāptaṃ phalena tu/
chindyād vikṣepamānāni tāny eṣām aṅgulāni tu// [sūryagrahaṇa]

Computed by: projectionScale