.children() method does not return jQuery object but Javascript object

.children() method does not return jQuery object but Javascript object

  1. <script type="text/javascript" src="javascript/jquery.js"></script>
  2. <script>
  3. $(function(){
  4.     var c = $('#parent').children();
  5.     alert(c[0]); // [object HTMLDivElement] this return the Javascript Object and not jQuery Object
  6.     alert(c[0].attr('id')); // Error : c[0].attr is not a function
  7.    
  8. </script>
  9. <span id="parent">
  10.     <div id="child">Child</div>
  11. </span>
Why the Children return Javascript object and not jQuery object ?
how to get jQuery object of those children ?

Thanks