Trigonometric parallax In order to use this method of calculating distance, two measurements are made of a star, one each at opposite sides of the Earth's orbit about the Sun. The star's position relative to the more distant background stars will appear displaced. The parallax value is considered to be the displacement in each direction from the mean position, equivalent to the angular displacement from observations one astronomical unit apart. The distance , in parsecs is found from the following equation,
Trigonometric parallax In order to use this method of calculating distance, two measurements are made of a star, one each at opposite sides of the Earth's orbit about the Sun. The star's position relative to the more distant background stars will appear displaced The parallax value is considered to be the displacement in each direction from the mean position, equivalent to the angular displacement from observations one astronomical unit apart. The distance , in parsecs is found from the following equation,