... Observing . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... Four spiral galaxies in Leo . ... Bulges affect galaxy formation . ... D avid Fisher, an astronomy graduate student at The University of Texas at Austin, is making important contributions to the future understanding of galaxy evolution by studying the different types of bulges at the hearts of nearby spiral galaxies. ... A bulge is a concentration of stars in the center of a spiral galaxy. ...