NGC 4991

NGC 4991 is a barred spiral galaxy in the constellation Virgo about 794 million ly from Earth. It spans roughly 140,000 ly, about the width of our Milky Way. The light reaching us tonight left it about 794 million years ago.

Because its light is 794 million ly from home, you are seeing NGC 4991 as it looked roughly 794 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). Distance computed by gravityfinder from redshift via Hubble's law (H0 = 70 km/s/Mpc).