Answer:
Luminosity is an intrinsic(natural) measurable property of a star independent of distance. The concept of magnitude, on the other hand, incorporates distance. The apparent magnitude is a measure of the diminishing(decrease) flux of light as a result of distance according to the inverse-square law.
Hope this helps!
https://www.nature.com/scitable/topicpage/genetic-mutation-1127
Velocity requires distance and speed
