Zodiac is imaginary belt of about 9 degrees north or south of the ecliptic , in which all the planets remain in movement except Pluto. The zodiac divided by 27 , gives 13 degrees 20 minutes that is one nakshatra. When 13 degrees 20 minutes is divided by 4, it gives result 3 degrees 20 minutes which is called one pada. Zodiac is divided into 108 parts (padas)
When zodiac is divided into three parts of 120 degrees each the rashis end at 120 degrees each. The rashis end at 120 degrees, 240 degrees, 360 degrees or say zero degree. These end points are called Gandanta. The Abhijit nakshatra is 276 degrees 40 minutes to 280 degrees 53 minutes 20 seconds. To calculate Abhijit Nakshatra 4th pada of Uttrashada 3 degrees 20 minutes zero seconds is taken and 1/15 part os Shravna nakshatra i.e. 53 minutes 20 seconds is added to it. Abhijit nakshatra of 4 degrees 13 minutes 20 seconds is calculated. Generally this nakshatra is used in Mahurta.
