As a caveat-this video could have been staged, obivously some time lapse was used, not sure. but it IS pretty cool and is I think the first time I have EVER seen Urasterias alive in a video! So, enjoy!
here's some better pics of the animal itself I found on Flickr
If you want to why/how the pedicellariae might be used in feeding click first on this intro post and then there's this earlier post about asteroids feeding on moving prey! (and on Labidiaster-the king of starfish predators on moving prey!)