The Moon, in his journey of the Zodiac, through the 27 constellations, creates the 27 Nakshatras,  which have been defined as the Lunar Mansions of Hindu Astronomy, each one of them occupying 13 degrees 20 minutes of the Zodiac.  

Chandra Siddhanta, Lunar Theory

This is the Equation given for the Moon’s largest perturbation. The Moon seems to be carried away by the immense gravitational pull of the Sun, causing its Ecliptic longitude to vary as much as  1.3 degrees. This has been referred to as the third major angle, Kendra,  between Sthithi & Mandoccha in Ganitha Nirnaya and as the second Anomaly in Greek Astronomy, anomaly being the angle between position and perihelion.

Third Kendra

Sin ( 2*T - Mc ) * 4467

  

Where Mc = Chandra Madhyamam, Mean longitude of Chandra, T = Thidhi = Longitude of Chandra – Longitude of Soorya

 
Working on Chandra  Siddhanta,
Major Theory of the Moon,
Fourteen Kendras, angles were plotted
By ace astronomers
Small, small Manda anomalies,
Angles between position & aphelion
As fourteen major perturbations
Of the Moon were identified !
 
The Essence of Sidddhantas Eighteen
Is the Sanskrit Ganita Nirnaya
Puliyoor studied  all eighteen
Plus Aryaabhaateeya, Maha Bhaskareeya,
Siddhantas  Arya, Brahma Sphuta
And came out with a gem
Based on Parameswara’s  Model Geometric !
 
The Longitude Corrected Thrice,
Manda, Parinathi  & Sheeghra
Manda means Reduction to  Heliocentric
Parinathi means Reduction to  Ecliptic
And Sheeghra means Reduction to  Geocentric
To get longitudes true !