oops, little typo---got to use `$Q` instead of `$` in my project.
wrote an extension method:

jQuery.fn.push = function( selector_or_nodes ) {
  //  Given a selector or a jQuery object, append all of the nodes to
the current jQuery object.
  var nodes = $is_string( selector_or_nodes )?
$Q( selector_or_nodes ) : selector_or_nodes;
  var node_count = nodes.length;
  for( var i = 0; i < node_count; i++ ) {
    this[ this.length++ ] = nodes[ i ] }; };

so if that should work, you can now say

  t.push( $( '.bar' ) );

and, in fact

  t.push( '.bar' );

while keeping the jQuery object identical.