NGC 4878

NGC 4878 is a lenticular galaxy in the constellation Virgo about 178 million ly from Earth. It spans roughly 79,000 ly, about 79% of our Milky Way's width. The light reaching us tonight left it about 178 million years ago.

Because its light is 178 million ly from home, you are seeing NGC 4878 as it looked roughly 178 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).