Yes, you're absolutely correct! When we observe distant stars in the night sky, we are essentially looking into the past. This is because light takes time to travel from its source to our eyes or telescopes. Since the universe is vast and stars are often located at significant distances from us, the light we observe from them has been traveling for many years, even millions or billions of years.
This means that by the time we see the light from a distant star, it may have already undergone changes or events that we are unaware of in the present. Some of the stars we see might have ceased to exist, either through stellar evolution or catastrophic events like supernovae, but we won't be aware of it until the light carrying that information reaches us.
For example, if a star located 10 light-years away were to explode in a supernova today, we wouldn't observe the supernova until 10 years in the future when the light from the explosion reaches us. So, in a sense, we are observing the star as it was 10 years ago.
This aspect of observing the universe is fascinating because it allows us to study the history and evolution of stars and galaxies. By observing distant objects, we can learn about the past states of the universe and gain insights into its development over time.
It's important to note that while it is theoretically possible for us to observe stars that no longer exist, it doesn't mean that all the stars we see are already gone. Many stars have lifetimes spanning millions or billions of years, and they can persist for a significant duration. The exact status of individual stars can be determined through further observation and analysis.