NGC 3966

NGC 3966 is a lenticular galaxy in the constellation Ursa Major about 151 million ly from Earth. It spans roughly 110,000 ly, about the width of our Milky Way. It is receding from us at about 3,433 km/s.

Because its light is 151 million ly from home, you are seeing NGC 3966 as it looked roughly 151 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).