Henize 2-10
This galaxy
looks at first to be a normal small
elliptical, but on closer examination it contains a mature
starburst, about 10 million years old, that was probably
started when Henize 2-10 swallowed an even smaller
galaxy. The picture, taken at
Tel Aviv University's
Wise Observatory,
shows the faintest parts of the Halpha emission
(the bright center is whited out); note the shells and
streamers of ionized gas and the little clump of emission
outside the main part of the galaxy on the right. That clump is
a small star cluster that formed at the end of the tidal tail that
remained after the little galaxy was swallowed.