Pentaceraster is another possibility but really most images of echinoderms on the net, if not identified by a scientist, should not be considered a sure ID. Many are definitely wrong.
Sometimes obviously so.
Anyway, several of these are very similar and without actually looking at the microscopically, it is impossible to really know for sure. This is true of many seastars in this hobby (eg not all "Linckia" are Linckia but are generally all in the same family). But without a doubt, it is in the Family Oreasteridae, which includes Protoreaster, Pentaster, Pentaceraster, etc and for sure none are reef safe. So if that is a concern, I wouldn't get it or keep it.