This NASA/ESA Hubble Space Telescope image features an uncommon galaxy with a striking appearance. NGC 7722 is a lenticular galaxy located about 187 million light-years away in the constellation Pegasus.
A lenticular, meaning “lens-shaped,” galaxy is a type whose classification sits between more familiar spiral galaxies and elliptical galaxies. It is also less common than spirals and ellipticals — partly because these galaxies have a somewhat ambiguous appearance, making it hard to determine if it is a spiral, an elliptical, or something in between. Many of the known lenticular galaxies sport features of both spiral and elliptical. In this case, NGC 7722 lacks the defined arms of a spiral galaxy, while it has an extended, glowing halo and a bright bulge in its center like an elliptical galaxy. Unlike elliptical galaxies, it has a visible disk — concentric rings swirl around its bright nucleus. Its most prominent feature, however, is undoubtedly the long lanes of dark red dust coiling around the outer disk and halo.
This new Hubble image, the sharpest taken of NGC 7722, brings the galaxy’s impressive dust lanes into sharp focus. Bands of dust like this are not uncommon in lenticular galaxies, and they stand out against the broad, smooth halo of light that typically surrounds lenticulars. Astronomers think NGC 7722’s distinctive dust lanes are the result of a …