IC 581
IC 581 is a spiral galaxy in the constellation Leo about 373 million ly from Earth. It spans roughly 110,000 ly, about the width of our Milky Way. The light reaching us tonight left it about 373 million years ago.
Illustration from its catalogued shape, not a photograph
Because its light is 373 million ly from home, you are seeing IC 581 as it looked roughly 373 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.
apartIC 582Barred spiral22 million ly
apartIC 570Spiral23 million ly
apartIC 572Spiral24 million ly
apartIC 571Barred spiral25 million ly
apartNGC 3040 NED02Lenticular27 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).