The X-axis of the H-R Diagram indicates the star's surface temperature in degrees Kelvin. The Y-axis, on the other hand, indicates luminosity, or brightness.
Main sequence refers to a roughly diagonal, slightly S-curved line stretching between the upper-left and lower-right corners on which main sequence stars chart. They maintain a predictable relationship between luminosity and temperature: the brighter, the hotter. The upper-right quadrant of the H-R diagram is home to newly discovered red giants while the lower-left quadrant of the H-R Diagram belongs almost exclusively to white dwarfs.
The time must be measured with respect to gravity. As it falls, it has free fall that is the force acting on it will be the gravity.With the distance in account, d = 1/2 gt²