Dwarf Irregular Galaxy NGC 4214 Imaged By Hubble WFC3
This is a full-field image of the nearby dwarf galaxy NGC 4214
taken with NASA's Hubble Space Telescope. Episodes of star
formation are revealed as the galaxy continues to form clusters
of new stars from its interstellar gas and dust. The Hubble
image reveals a sequence of steps in the formation and
evolution of stars and star clusters, evident in the glowing gas
surrounding bright stellar clusters.
The young clusters of new stars appear within bright clumps of
glowing gas. Each cloud glows because of the strong
ultraviolet light emitted from the embedded young stars, which
have formed within them due to the gravitational collapse of
the gas. These hot stars also eject fast "stellar winds" moving
at millions of miles per hour (thousands of kilometers per
second), which plow into the surrounding gas. The radiation
and wind from the young stars literally blow bubbles in the gas.
The main object near the center of the galaxy is a cluster of
hundreds of massive blue stars, each more than 10,000 times
brighter than our Sun. A vast heart-shaped bubble, inflated by
the combined stellar winds and radiation pressure, surrounds
the cluster. The bubble will increase in size as the most
massive stars in the center reach the ends of their lives and
explode as supernovae.
NGC 4214 provides a unique view of star formation in galaxies
other than the Milky Way because of its proximity to us. Filters
onboard Hubble also help to tell the story of star formation in
this galaxy. Broadband filters expose light from older star
populations and show the overall structure of the galaxy. NGC
4214 is not only small in size compared to the Milky Way, it
also appears irregular in shape, with no defined disk or spiral
arms. Ultraviolet filters show the intense stars that radiate
ultraviolet light in the centers of the colorful nebulosity, which
is in turn visible because of narrow-band filters that isolate
specific gases, such as hydrogen, nitrogen, and oxygen.
This dwarf galaxy resides 10 million light-years away in the
constellation Canes Venatici. The Hubble images were obtained
in December 2009 with the Wide Field Camera 3 in ultraviolet
and visible filters.
Credit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-
Acknowledgment: R. O'Connell (University of Virginia) and the
WFC3 Scientific Oversight Committee