What is the approximate lower boundary for an object to qualify as a true star capable of sustained hydrogen fusion?

Answer

$0.075$ to $0.09$ solar masses

The lower boundary for sustained hydrogen fusion, which distinguishes a star from a brown dwarf, is cited as being around $0.075$ to $0.09$ solar masses.

What is the approximate lower boundary for an object to qualify as a true star capable of sustained hydrogen fusion?
astronomystarmass