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

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heliacal rising of Agastya. They are so termed, because
they indicate the Kāla or the time in between the rising
of the star and the Sun which signifies the moment of its
heliacal rising. Indirectly therefore these Kālāmsas indi-
cate which star is of which magnitude. A star which has
12° as Kālāmsas is therefore of first magnitude ; and as
the Kālāmsas increase, the magnitude also increases. It
will be rembered that the higher the magnitude of a star,
the fainter it will be and not the brighter as is likely to be
misconstrued by lay people.
Verse 9. To compute the moment of conjunction of
a planet and a star.
The Āyana-Dṛk-Karma is to be done as mentioned
before (with respect to the planet) and the Sphutasara is
to be computed to know the time of (polar latitudinal)
conjunction.
Comm. We are directed to use the polar longitude
and polar latitude with respect to the planet because this
kind of conjunction will be more conspicuous than a
celestial latitudinal conjunction because the Ecliptic is
far more inclined than the Equator with respect to the
horizon.
Verses 10, 11.
The difference in the longitudes of the planet and the
star, divided by the daily motion of the planet, gives the
number of days approximately after or before the moment
of conjunction.
If the planet be retrograde, the conjunction past or
future will be in the reverse ie. future or past.
Comm. Let x and y be the polar longitudes of the
planet and the star and let x<y. Since y is constant as
the star has no motion, x has to increase to the extent of