How many light years does it take for the light of the star nearest to the sun to reach the earth

How many light years does it take for the light of the star nearest to the sun to reach the earth

Proxima Centauri is the third star of the alpha triad Centauri, also known as Alpha Centauri C. It is the closest star to the sun (4.22 light-years)

Suppose a star like the sun is at least light-years away from the earth?
It is better to give the calculation formula and the relationship between absolute magnitude and apparent magnitude

Your topic is wrong. Should it be "at most"?
It's a sixth order star about 40 light-years away. Barely visible to the naked eye
The relationship between absolute magnitude and apparent magnitude is as follows:
M=m+5－5 log d
M is absolute magnitude; m is visual magnitude; D is distance

How far is Altair and Vega from the earth? Thank you!
Simple point on the line, as long as you say the distance is OK, do not have a long speech

Altair is 16.3 light-years away from earth
Vega is 26.4 light-years from earth