सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)

518 Astārka C₁′; but C₁′ will have now a longitude less than C which is incongruous. In such a situation, Bhāskara says, there is no question of the star setting heliacally at all. This is indeed, an ingenious mathematical presentation of a physical pheno- menon, which reflects credit to Bhāskara's genius. Verse 16. Circumpolar stars or Sadōdita stars. If a star has a northern declination greater than 90–ϕ (ie. ϕ > 90–δ) it will be always above the horizon ; also if the southern declination is greater than 90–ϕ such a star will never be seen in a northern latitude, be it Lubdhaka or Agastya or even a planet for the matter of that. Comm. (Vide fig. 122) Let S₁ be a star such that PS₁′ < PN ie. 90–δ < ϕ ie. δ > 90–ϕ. It is clear from the figure that its diurnal path is entirely above the horizon. It is called a Sadōdita star or circumpolar. Take the case of S₂. Its southern declination ie. QS₂′ is greater than the lamba (90–ϕ) ie. QS. It is evident from the figure that its diurnal path is entirely below the horizon. Bhāskara gives two examples here namely (1) where the latitude is greater than 37°, there Agastya will not be visible (having a great north-polar distance), (2) where the latitude is greater than 52°, there Abhijit is always above the horizon (having a small north-polar distance). Bhāskara adds, ‘even a planet’. This will be true, for example, in a high latitude say 89°. Suppose the southern declination of a planet is greater than 1°. On that day and for some more days also, the planet’s diurnal paths will be below the horizon as will be clear from a figure.