One of the most jarring things about astronomy is that when one looks at the sky, one is looking at the past. And it’s not uniform. Sirius looks as it did 6 and a fraction years ago. Betelgeuse as it did 700 or 800 years ago (several estimates of it’s distance). .Indeed, it’s something that astronomers seem to forget when they try to come up with models of the Milky Way. Something 10,000 light years away is going to look like it did 10,000 years ago and something 100 light years away looks like it did 100 yaers ago.