What Does Radial Velocity Tell Us? A positive radial velocity indicates the distance between the objects is or was increasing; a negative radial velocity indicates the distance between the source and observer is or was decreasing. What can we learn from radial velocity? The radial velocity technique is able to detect planets around low-mass stars,
What Can We Learn From Radial Velocity? The radial velocity technique is able to detect planets around low-mass stars, such as M-type (red dwarf) stars. This is due to the fact that low mass stars are more affected by the gravitational tug of planets and because such stars generally rotate more slowly (leading to more
How Do You Find The Velocity Of A Galaxy? Thus, we can determine the velocity of a galaxy from its spectrum: we simply measure the (shifted) wavelength of a known absorption line and solve the equation v = z * c. We find that z = 50/5000 = 0.001 and conclude that this galaxy is