A group of stars in the sky is called a constellation. Generally it is associated with the path of the moon, but in reality it is appropriate to call any constellation as a constellation. At one place in the Rigveda, the Sun is also called a constellation. The other constellations are Saptarishi and Agastya.
The Moon orbits the Earth in 27.3 days and passes through 27 groups of stars during this 360-degree orbit. This synergy and conjunction of the Moon and the clusters of stars is called Nakshatra. The group of 27 stars through which the Moon passes, are known by the names of 27 different constellations.
