Spiral galaxy NGC 3370 is roughly the same size and general layout as our Milky Way. It’s about 100 million light-years away in the direction of the constellation Leo. It dominates the foreground of this Hubble image (click it to embiggen) which shows other galaxies scattered in the background. This particular picture is detailed enough for study of individual pulsating stars known as Cepheid variables that can be used to accurately determine the distance to the galaxy. NGC 3370 is also home to a recent type Ia supernova. Combining the known distance to this “standard candle” supernova and the Cepheid data with observations of other supernovae at even greater distances has been useful in refining estimates of the age and expansion rate of the Universe.
Image Credit: NASA