NGC 3138
NGC 3138 is a barred spiral galaxy in the constellation Hydra about 369 million ly from Earth. It spans roughly 120,000 ly, about the width of our Milky Way. The light reaching us tonight left it about 369 million years ago.
Illustration from its catalogued shape, not a photograph
Because its light is 369 million ly from home, you are seeing NGC 3138 as it looked roughly 369 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 3140Spiral40 million ly
apartNGC 3141Spiral42 million ly
apartNGC 3280AElliptical47 million ly
apartNGC 3280CElliptical49 million ly
apartNGC 3133Barred spiral56 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).