Book excerpt: Indian astronomical texts give the coordinates of the yogataras or junction stars of nakshatras. These coordinates have been interpreted as polar coordinates, which depend on the position of the north celestial pole. Polar coordinates of a star should change with time due to precession. However, different astronomical texts written over many centuries give same coordinates for most yogataras. This has resulted in Indian astronomers being called incompetent, who did not observe the positions of the stars with accuracy. In this book it is proposed that Indian astronomers were using sidereal ecliptic coordinates, which do not change with time to a significant extent. This understanding has led to the discovery of the original boundaries of nakshatras. Based on these boundaries of nakshatras and the changing position of sun in the background of nakshatras during solstices, the dates of astronomical text Vedanga Jyotisha and astronomer Varahamihira have been reexamined. Based on the zero points of Vedic astronomy, the values of ayanamsha have been calculated.