NGC 648
NGC 648 is an elliptical galaxy in the constellation Cetus about 503 million ly from Earth. It spans roughly 160,000 ly, about 1.6 times the width of our Milky Way. The light reaching us tonight left it about 503 million years ago.
Illustration from its catalogued shape, not a photograph
Because its light is 503 million ly from home, you are seeing NGC 648 as it looked roughly 503 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.
apartNGC 540Lenticular38 million ly
apartIC 141Barred spiral49 million ly
apartNGC 555Lenticular53 million ly
apartNGC 539Spiral55 million ly
apartIC 1745Lenticular65 million ly
apart
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).