Baby Starfish?

This little guy hitchhiked into the tank. I am trying to determine what it is. I was unable to get a decent picture as it is so small. I think it might have been an asterina starfish. But I am unsure. I am curious what your opinions might be. Nuisance or welcome guest? Is it in fact an Asterina? thanks,

 

You're correct in your ID. How reef safe will depend on type and there are many. It's on the glass which is a good sign. Most commonly found ones are algae eaters. If you start to have issue with zoanthids you may have ended up with a coral eater. Watch population numbers. They reproduce via lateral fission, basically arms becoming other star fish and so and so forth.

 

Awesome thanks