Spiral galaxy NGC 4414 was first imaged by the Hubble Space Telescope (HST) in 1995. Because of its size, only half of the galaxy observed was visible in the datasets at that time. Four years later the Hubble Heritage Team completed its portrait of the galaxy, also using the Hubble's Wide Field Planetary Camera 2 through the same three color filters.
The central regions of the galaxy contain primarily yellow and red stars, indicating that they are relatively older than the younger bluer stars in the outer spiral. Rich clouds of interstellar dust, seen as dark patches and streaks, appear in silhouette against the starlight.
By carefully measuring the brightness of variable stars in NGC 4414, HST Key Project, astronomers have determined the distance to this galaxy at 19.1 megaparsecs or about 60 million light-years. This information, along with calculated distances to other nearby galaxies, helps astronomers estimate the rate at which the universe is expanding. The Hubble constant (H0) is the ratio of the speed at which galaxies are moving away from us to their distance from us. This value is used, among other things, to help us determine the very age of the universe.
Credit: Material created with support from AURA/SCScI from NASA contract
