Stars under headin starting at first non-space character

I am using this bash function to print a phrase with stars below it.
Am looking at how the implementation can be simplified?

Code:outline ()
{
titl="$1"
n="${#titl}"

# extract leading spaces
[[ $titl =~ ^(\ )* ]]; spaces="${BASH_REMATCH[0]}"

# remove leading spaces from titl
titl="${titl/#$spaces/}"

echo "$spaces$titl"
echo "$spaces${titl//?/*}"
}Invoking the following commands

Code:outline "Linux Questions"
outline " Linux Questions"results in

Code:Linux Questions
***************
Linux Questions
***************