NGC 5717

NGC 5717 is a lenticular galaxy in the constellation Boötes about 515 million ly from Earth. It spans roughly 150,000 ly, about 1.5 times the width of our Milky Way. The light reaching us tonight left it about 515 million years ago.

Because its light is 515 million ly from home, you are seeing NGC 5717 as it looked roughly 515 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).