Final answer:
If Sirius were moved to a distance 5 times further from Earth, the parallax angle would decrease due to the inversely proportional relationship between distance and the parallax angle.
Step-by-step explanation:
If Sirius was magically moved to a distance 5 times as far from Earth as it is now, the parallax angle would get smaller. Parallax is the apparent shift in the direction of an object due to the motion of the observer. In the case of stellar parallax, this is the shift in the apparent direction of a star due to Earth's orbital motion. Astronomers define parallax as one-half the angle that a star shifts when seen from opposite sides of Earth's orbit. This is measured against a baseline of 1 astronomical unit (AU), which is the average distance from the Earth to the Sun.
According to the properties of parallax, as the distance to a star increases, the parallax angle decreases. This is because the star's apparent movement against the background stars would be less noticeable from Earth. The relationship between the star's distance and the parallax angle is inversely proportional.