NGC 3945

NGC 3945 is a lenticular galaxy in the constellation Ursa Major about 58 million ly from Earth. It spans roughly 94,000 ly, about the width of our Milky Way. It is receding from us at about 1,220 km/s.

Because its light is 58 million ly from home, you are seeing NGC 3945 as it looked roughly 58 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).