NGC 3370: A Sharper
View
Similar in size and
grand design to our own Milky Way, spiral galaxy NGC 3370 lies about 100 million light-years away
toward the constellation Leo.
Recorded here in exquisite detail by the Hubble Space Telescope's Advanced
Camera for Surveys,
the big, beautiful face-on spiral does steal the show, but the sharp image also
reveals an impressive array of background galaxies in the field, strewn across
the more distant Universe.
Looking within NGC
3370, the image data has proved sharp enough to study
individual pulsating stars known as Cepheids that can be
used to accurately determine this galaxy's distance.
NGC 3370 was chosen for
this study because in 1994 the spiral galaxy was also home to a well-studied
stellar explosion -- a type Ia supernova.
Combining the known
distance to this standard candle supernova, based on the Cepheid measurements, with
observations of supernovae at even greater distances, can reveal the size and expansion rate of the Universe itself.
