NGC 3540

NGC 3540 is a lenticular galaxy in the constellation Ursa Major about 297 million ly from Earth. It spans roughly 110,000 ly, about the width of our Milky Way. It is receding from us at about 6,387 km/s.

Because its light is 297 million ly from home, you are seeing NGC 3540 as it looked roughly 297 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).