10 ASTRONOMY t FEBRUARY 2014
A colorful
menagerie
Many people think of
globular star clusters as
old and boring. The old
part is true, but this recent
Hubble image of M15 in
Pegasus shows “boring”
should not be part of our
globular vocabulary. This
dense cluster lies some
35,000 light-years from
Earth and contains more
than 100,000 stars. The
brightest ones are rela-
tively cool red giants that
glow with a golden hue.
The hottest stars shine
with a striking bluish
color. Hubble’s Wide Field
Camera 3 and Advanced
Camera for Surveys cap-
tured this image through
filters sensitive to infra-
red, optical, and ultra-
violet light. NASA/ESABREAK
THROUGH