The stellar magnitude \(M\) of a star is approximately \(-2.5 \log \left(B /
B_{0}\right),\) where \(B\) is the brightness of the star and \(B_{0}\) is a
constant.
a. If you plotted \(B\) on the horizontal and \(M\) on the vertical axis, where
would the graph cross the \(B\) axis?
b. Without calculating any other coordinates, draw a rough sketch of the graph
of \(M\). What is the domain?
c. As the brightness \(B\) increases, does the magnitude \(M\) increase or
decrease? Is a sixth-magnitude star brighter or dimmer than a first-magnitude
star?
d. If the brightness of a star is increased by a factor of \(5,\) by how much
does the magnitude increase or decrease?