No, this fuzzy spot at the center of the picture is not a reflex from the overwhelmigngly bright star Regulus below. It is probably one of the most peculiar objects accessible for small and medium sized amateur instruments. It is a dwarf galaxy closer to us than even the local counterpart to our home galaxy, M 31. "Only" 800 000 light years away, it is one of the few extragalactic objects that allow to resolve stars even in medium-sized telescopes. A close look at the larger version reveals the subtle granularity which indicates that the object actually consists of stars. The dwarf galaxy is sometimes referred as "Leo I" instead of the number under which it is listed in the Uppsala Galaxy Catalog.
Of course, the proximity to Regulus, one of the brightest stars in the spring sky, is a challenge to any astrophotography system. The brightest stars in Leo I are 30.000,000 times fainter than Regulus, but only less than half the diameter of the full moon apart.