Keyup event listener fires when enter is pressed on Chrome's Ominbox

In chrome browser, when using this snippet:

  $(document).on('keyup', function(){
    alert("Hey");
  });

Every time I press enter in the url bar (for example when I cut and paste the url of the page itself) the event listener fires. Why does it happen?

EDIT:

It surprised me because url bar is not in document (maybe in window?) and firefox does not have this behaviour. When I look for e.target, Chrome Inspector shows body.

I thought this could be caused by event bubbling so I tried this:

  $(document).on('keyup', function(e){
    e.stopPropagation();
    alert("Hey");
  });

But it doesn't work. How can I prevent it from being triggered?