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Encyclopedia of Science  elliptical galaxy  The giant
elliptical, M87 A galaxy that has a superficially smooth,
featureless appearance and an ellipsoidal shape. Giant
ellipticals, such as M87, may contain over 10 trillion solar
masses in the form of stars, are among the largest of galaxies,
and are often found at the heart of rich clusters of galaxies.
Dwarf ellipticals, on the other hand, such as M32 (a satellite
of the Andromeda Galaxy) may have masses as low as 10 million
solar masses and lie at the bottom end of the galactic size
range. Normal ellipticals are quite rare throughout much of
space, but form the majority in big clusters. It used to be
thought that ellipticals were the oldest galaxies, but more
recent studies, including computer simulations, suggest that
they have formed from collisions and mergers between spiral
galaxies. So-called starburst galaxies appear to show this
process in action.  Many old ideas about ellipticals have been
shaken