NGC 4721

NGC 4721 is a lenticular galaxy in the constellation Coma Berenices about 356 million ly from Earth. It spans roughly 87,000 ly, about the width of our Milky Way. It is receding from us at about 7,858 km/s.

Because its light is 356 million ly from home, you are seeing NGC 4721 as it looked roughly 356 million years ago. The photons left before that much of history had passed, and are only now reaching us. This distance is estimated from the galaxy's redshift, so the lookback time is approximate.

Source: structural data (position, morphology, brightness, redshift) from OpenNGC (CC BY-SA). Recession velocity from RC3 (de Vaucouleurs et al. 1991, via NASA/HEASARC, public domain). Distance computed by gravityfinder from redshift via Hubble's law (H0 = 70 km/s/Mpc).