If a star emitting yellow light is accelerated towards the Earth,then to an observer on Earth,it will appear:

$A$ spectral line $\lambda = 5000\ \mathring A$ in the light coming from a distant star is observed as $5200\ \mathring A$. What will be the recession velocity of the star?

The periodic time of rotation of a certain star is $22$ days and its radius is $7 \times 10^8 \ m$. If the wavelength of light emitted by its surface is $4320 \ \mathring{A}$, the Doppler shift will be $(1 \ day = 86400 \ s)$

The Doppler effect in sound,in addition to the relative velocity between the source and the observer,also depends on the individual motion of the source and the observer relative to the medium. However,the Doppler effect in light depends only on the relative velocity between the source and the observer. The reason for this is:

What speed (in $km/s$) should a galaxy move with respect to us so that the sodium line at $589.0 \;nm$ is observed at $589.6 \;nm$?

Hubble showed that the universe as a whole is expanding and the distant stars are receding from us. The spectral line from a star,when compared with the corresponding line from a stationary source,will then show: