NGC 3815

NGC 3815 is a spiral galaxy in the constellation Leo about 170 million ly from Earth. It spans roughly 71,000 ly, about 71% of our Milky Way's width. It is receding from us at about 3,725 km/s.

Because its light is 170 million ly from home, you are seeing NGC 3815 as it looked roughly 170 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).