The formula to calculate the Star Distance (Dstar) is:
\[ D_{star} = \frac{1}{P} \]
Where:
Let's say the parallax angle (P) is 0.1 arc-seconds. Using the formula:
\[ D_{star} = \frac{1}{0.1} = 10 \]
So, the Star Distance (Dstar) is 10 parsecs.