What Is a Nakshatra?
The Moon's path is split into 27 equal parts of 13°20'. Each one is a nakshatra, or star. The Moon takes about a day to cross one.
In Kerala, the star at sunrise is the naal of the day. Birthdays are celebrated on it. Temple offerings are booked by it. And the birth star is the first thing an astrologer asks for.
Each nakshatra has four padas of 3°20'. The pada at birth decides the first letter of the name and the starting dasha.