The twelf zodiacal signs are related to the Sun. Nakshatras are closer related to the Moon. The full power of Vedic astrology can only be achieved when both systems - Rasi and Nakshatra based - are used in combination.
Most Nakshatra techniques are based upon a circle of 27 Nakshatras.
Nevertheless it is written that there are 28 Nakashatras, but the 28th (Abhijit) is hidden in Kali Yuga. So methods that use the 28 Nakshatra system are supposed to be very old. Most important of these is Sarvatobhadra.
A quarter part of a Nakshatra is called a Pada (i.e. foot).
Nakshatras have a span of 13°20', so a Pada is 3°20' - which is the span of Navamsa, too. Navamsa and Nakshatra Pada are the same.
Navamsa is the bridge between zodiac (Sun) and the stars (Moon). This is a deeper reason why the Navamsa chart is so closely related to partnership and marriage.
Each Nakshatra has a planetary lord used for Vimsottari Dasa and K.P. calculations. The years assigned to the signs are the Mahadasa durations of Vimsottari Dasa.
|1||Aswini, Magha, Moola||Ketu||7|
|2||Bharani, Poorvaphalguni, Poorvashadha||Venus||20|
|3||Krittika, Uttaraphalguni, Uttarashadha||Sun||6|
|4||Rohini, Hasta, Sravana||Moon||10|
|5||Mrigasira, Chitra, Dhanista||Mars||7|
|6||Ardra, Swati, Satabhisha||Rahu||18|
|7||Punarvasu, Visakha, Poorvabhadra||Jupiter||16|
|8||Pushyami, Anuradha, Uttarabhadra||Saturn||19|
|9||Aslesha, Jyeshta, Revati||Mercury||17|
Special Nakshatras are counted from the birth star. These Nakshatras have special significations, e.g. on transits of other planets.
|Name of Nakshatra||Number|