NGC 5817

NGC 5817 is a lenticular galaxy in the constellation Libra about 337 million ly from Earth. It spans roughly 100,000 ly, about the width of our Milky Way. The light reaching us tonight left it about 337 million years ago.

Because its light is 337 million ly from home, you are seeing NGC 5817 as it looked roughly 337 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).