Laravel, Eloquent: SQL query with left join

If the query needs parentheses/brackets for a where condition like below Normal SQL:

SELECT users.fname, planets.name 
FROM  users
LEFT JOIN  planets ON (users.planet_id = planets.id)
WHERE users.lname LIKE '%hawk%' 

ELOQUENT SQL:

$name = "hawk";

$userResults = DB::table('users')
       ->leftJoin('planets', function($join) {
         $join->on('users.planet_id', '=' , 'planets.id');
        })
       ->where('users.lname' , 'like', '%'.$name.'%')
       ->get(array('users.fname', 'planets.name'));