These objects' luminosity can be described by raising sigma, which is the velocity dispersion for central-line of sight, to n, in a relationship known as the Faber-Jackson relation.  
These objects' luminosity can be described by raising sigma, which is the velocity dispersion for central-line of sight, to n, in a relationship known as the Faber-Jackson relation.  The tight correlation between their luminosity, radius, and velocity dispersion is known as the "fundamental plane." Due to their relatively low amount of interstellar matter, new stars tend not to form in them. The Hubble classification describes these objects based on their projected flatness, and the dwarf type have been hypothesized to be the most abundant type in the near universe.  FTP, identify these types of galaxies distinct from lenticular and spiral galaxies, that approximate the shape of a certain conic section.
These objects' luminosity can be described by raising sigma, which is the velocity dispersion for central-line of sight, to n, in a relationship known as the Faber-Jackson relation.  
{Elliptical} Galaxies