BBC News | SCI/TECH | Spiral Galaxy Stays Young At Heart Andrew Stephens, Ohio State University. Before now it was thought that the central bulge and disk of spiral galaxies were made up of stars of different ages. http://news.bbc.co.uk/hi/english/sci/tech/newsid_1369000/1369458.stm
Extractions: Andrew Stephens, Ohio State University Before now it was thought that the central bulge and disk of spiral galaxies were made up of stars of different ages. Astronomers thought that older stars inhabited the central bulge and younger stars were to be found in the disk. But some of the first images of galaxy M33 have shown that it has far fewer than expected older stars in its bulging heart. Cosmic corpulence Astronomers have long thought that a typical galactic disk is made up of stars of all ages. The central 'bulge' of a disk normally contains old stars from the time the galaxy formed. This is one reason why studying bulges can tell astronomers about how galaxies formed and evolved. According to current theory, spiral galaxies begin as a giant rotating mass of gas and dust, which starts out in a roughly spherical shape before the edges flatten into a disk.
Very Small Galactic Bulge Could Change Ideas Of Galaxy Formation The density of stars in the region more closely resembles a galactic disk than a bulge as if the disk extended to the very core of M33, said Andrew Stephens http://www.sciencedaily.com/releases/2001/06/010605080041.htm
Extractions: Source Ohio State University Date Print this page Email to friend COLUMBUS, Ohio The nearby galaxy M33 has a much smaller central bulge than astronomers had previously thought or perhaps no bulge at all, according to astronomers at Ohio State University. The finding may expand current theories of how spiral galaxies form. Galaxy Invading Milky Way; Apparently Contains Much Unseen Matter Skinny Galaxy Has Supermassive Black Hole At Core, Just Like Bulging Galaxies Catalog Of Spiral Galaxies Shows Evidence Of Galactic Collisions related stories Related section: Galaxies such as M33 are called spiral galaxies because pinwheel-shaped arms of gas, dust, and stars extend directly out from a spherical nucleus of stars at the center, giving the galaxy a flattened disk shape. The spherical nucleus is called a bulge, because it normally bulges out from the disk.
