The zodiac is now divided into 27 constellations with each part occupying 360 divided by 27 (360/27) or approximately 13 degrees and 20 minutes of angle. This is shown in the figure below:
Note that each Constellation (नक्षत्र) has a fixed pie slice (sector) in the zodiac. Ashiwini occupies the first slice from 0 degrees to 13 degrees and 20 minutes. Bharani occupies 13deg20mins to 26deg40mins and so on. You will use this information when you study Vishontari Dashas (विशोंतरी दशा) in the subsequent lessons.