Question

question 1
1 pts
if a star has a large luminosity and also a low surface temperature then it must have

a large parallax.

a small parallax.

a large radius

a small radius.

Explanation:

The luminosity of a star \( L \) is related to its surface temperature \( T \) and radius \( R \) by the Stefan - Boltzmann law \( L = 4\pi R^{2}\sigma T^{4}\) (where \(\sigma\) is the Stefan - Boltzmann constant). If \( L \) is large and \( T \) is low, to satisfy the equation, \( R \) must be large. Parallax is related to the distance of the star from Earth (\(d=\frac{1}{p}\), where \(p\) is the parallax angle) and not directly to luminosity and temperature.

Answer:

a large radius