"Dwarf elliptical galaxies, such as NGC 185, pose a complex and
little understood problem that might even be said to have a
'social' guise among astrophysicists," explains Aparicio, who
heads the IAC's Stellar Populations group, which has carried out
the study. This is because these galaxies were directly involved
in the construction of one of the key paradigms of the
astrophysics of this century: the concept of stellar
populations, introduced by Walter Baade (1893-1960), an
astronomer at the Carnegie Institute in Pasadena (California,
USA). In the 1940s, Baade carried out a major synthesis of that
imposed order on the chaos of apparently unconnected data in
circulation among astronomers at the time concerning the
properties of various types of stars in the Milky Way and other
galaxies. As a result of this work, he introduced the concepts
of Populations I and II. The latter essentially included the
oldest stars, which were characterized by being very red. "One
interesting aspect, which seemed at the time to b