NGC 4603

NGC 4603 is a spiral galaxy in the constellation Centaurus about 121 million ly from Earth. It spans roughly 92,000 ly, about the width of our Milky Way. It is receding from us at about 2,440 km/s.

Because its light is 121 million ly from home, you are seeing NGC 4603 as it looked roughly 121 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).