Debark it, and seal the ends with some type of water proof sealant like polyurethane or shellac to prevent checking. If you're going to make a bow that bends through the handle you probably dont want to split a stave this thin, you'll probably want the full thickness for the handle. Be extra careful when debarking that you do not damage the outer growth ring. I'm new to this myself but I'm sure more experienced folks will weigh in. Good luck and welcome.