The Hubble Space Telescope accumulated approximately 555 hours of exposure time to capture this Hubble eXtreme Deep Field image. The area shown represents a seemingly empty patch of sky about the width of a toothpick when held at arm's length. The picture contains only two foreground stars (indicated by surrounding spikes). Every other object is a galaxy. The most distant galaxies' light is reddened by the expansion of the universe. We're seeing light that left them 13.2 billion years ago.
This image is the combined total of over 2000 separate images, and the total exposure is a whopping two million seconds, or 23 days! It's based on the original Hubble Ultra Deep Field, with new observations added in since the originals were done. It shows over 5500 galaxies - nearly everything you see in the picture is a galaxy, an island universe of billions of stars. Only a handful of individual stars in the foreground of our own galaxy can be seen.