NGC 391

NGC 391 is an elliptical galaxy in the constellation Cetus about 249 million ly from Earth. It spans roughly 71,000 ly, about 71% of our Milky Way's width. The light reaching us tonight left it about 249 million years ago.

Because its light is 249 million ly from home, you are seeing NGC 391 as it looked roughly 249 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).