IC 3603

IC 3603 is an elliptical galaxy in the constellation Coma Berenices about 645 million ly from Earth. It spans roughly 68,000 ly, about 68% of our Milky Way's width. The light reaching us tonight left it about 645 million years ago.

Because its light is 645 million ly from home, you are seeing IC 3603 as it looked roughly 645 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). Distance computed by gravityfinder from redshift via Hubble's law (H0 = 70 km/s/Mpc).