Great Bear is a

According to the pulsating theory,the expansion and contraction of the universe repeats after every

How does the red shift confirm that the universe is expanding?

Two stars situated at distances of $1$ and $10$ light years respectively from the earth appear to possess the same brightness. The ratio of their real brightness is

The rate of solar energy incident on a unit area of the Earth is approximately ....... $(kW/m^2)$.

Which of the following is not true about the total lunar eclipse?