The formula to calculate the distance to a star (d) is:
\[
d = \frac{1}{p}
\]
Where:
\( d \) is the distance to the star in parsecs
\( p \) is the parallax angle in arcseconds
Definition
Parallax Angle (p): The apparent shift in position of a nearby star against the background of distant objects when observed from two different positions in Earth's orbit around the Sun. This shift is measured in arcseconds.
Distance to the Star (d): The distance to the star in parsecs, calculated using the parallax angle.
Significance: By measuring the parallax angle, astronomers can determine the distance to the star using trigonometry. The smaller the parallax angle, the further away the star is. This method is fundamental in the field of astrometry for measuring stellar distances.
Example
Let's say the parallax angle (p) is 0.1 arcseconds. Using the formula:
