The Dragonfly Nearby Galaxies Survey. II. Ultra diffuse galaxies near the elliptical galaxy NGC 5485

Understand

We present the unexpected discovery of four ultra diffuse galaxies (UDGs) in a group environment.

• We recently identified seven extremely low surface brightness galaxies in the vicinity of the spiral galaxy M101, using data from the Dragonfly Telephoto Array.
• The galaxies have effective radii of $10"-38"$ and central surface brightnesses of $25.6-27.7$ mag arcsec$^{-2}$ in g-band.
• We subsequently obtained follow-up observations with $HST$ to constrain the distances to these galaxies.