For a star similar in mass to the Sun, approximately how much can its total luminosity increase upon becoming a Red Giant?

Answer

By a factor of 1,000 to 10,000.

The text specifies that for a star like the Sun, the transition to a red giant can increase its luminosity by a factor ranging from 1,000 to 10,000 times its former output.

For a star similar in mass to the Sun, approximately how much can its total luminosity increase upon becoming a Red Giant?
astronomystarsstellar evolutionred giantsLuminositymain sequence stars