Sirius is about 9.0 light-years from Earth.

Question

To reach the star by spaceship in 10 years (ship time), how fast must you travel?
How long would the trip take according to an Earth-based observer?
How far is the trip according to you?

Answer 1

Your question spurred me to look up the topic, being totally unfamiliar with it at this point.

I found it stated that Einstein’s special theory of relativity states that the time scale of an object moving at high speed is shortened in accordance with

……………t/t(o) = 1/sqrt[1 – (v^2/c^2)] where

t = the travel time to Sirius in seconds as observed by a person on Earth
t(o) = the travel time to Sirius as observed on a clock on the spaceship (10 years)
c = the speed of light = 186,300 m/s
v = the velocity of the spaceship as viewed by an observer on Earth
v(o) = the velocity of the spaceship as viewed by an observer on the spaceship
Let d = the distance from Earth to Sirius in miles = 9 light years

Given the information you offered, you should be able to derive the answers you seek.

Note that many scientists regard the contraction of time as a real phenomenon while others maintain that it is merely apparent.

A google search will undoubtedly provide you with much more information.