Awesome videos sir! Can you please also do a video on the rotational curve of galaxies and how rotational velocities of distant stars in milky way were found. Particularly in the context of Vera Rubin's observations of 1970s.
Any way to measure the direction of travel as seen from the telescope. This tells us the absolute +/- value of the radial velocity, right? But we don't know if it's coming right at us slowly or at some angle and miss us, as in the diagram.
This is essentially the Doppler Shift formula....at relativistic speeds, the equation is : nu=nu0×sqrt (c-u)/(c+u)...this is for redshift...for blueshift we take the reciprocal of the term inside the square root.... Hope it helps...😄😄
