Auhors in Menu

Have this in my notes but not sure I’ve ever tested it:

Easy way to get all the authors for posts in a certain category?

$post_ids = implode(',', get_objects_in_term($term_id, 'category'));

$authors = $wpdb->get_results("
SELECT DISTINCT *
FROM $wpdb->users u
JOIN $wpdb->posts p ON (p.author_id = u.ID)
WHERE p.ID IN ('$post_ids')
");