Find owner information of an entity ( elgg 1.7 )

Could someone explain to me how to retrieve user information, such as are name, icon, ... on a page that displays an entities knowing that I can display the owner_guid, but when I go owner_name I have nothing ...

My PHP Code

  if ($vars['entity']->canEdit()) {
 echo 'do nothing';
} else {
  echo $vars['entity']->heading;
  echo $vars['entity']->owner;
  echo $owner->name; //* doesn't work ...
   } ?>

Thanks ;)