To get 47,000 stars you need 2 hamsters(breed does not madder). And unlock robo ham.Now put the 2 hamsters in the same cage. Then put robo ham in with them. Leave your NDS on all day and night and half a day(Make sure your NDS is charging).
Now check on the hamsters. If the hamsters liked the robo ham, you should have 47,000 stars!!!