Yes, you are absolutely correct. When we observe distant stars in the night sky, we are indeed looking into the past. The light from these stars takes time to travel across the vast distances of space to reach us, and that means we see them as they were in the past, not as they are in the present.
The stars we observe in the night sky are typically located at varying distances from Earth, and the light we receive from them has traveled for different lengths of time. For instance, if a star is located 10 light-years away, the light we observe from that star today actually left the star 10 years ago. So, in a sense, we are seeing the star as it appeared 10 years ago.
Given this time delay, it is possible that some of the stars we observe may no longer exist in their previous form. It is entirely plausible that a star we see in the night sky could have undergone significant changes, including supernova explosions or other catastrophic events, since the light left the star. However, we would not be aware of these changes until the light from those events reaches us.
In fact, some astronomical observations have captured the light from distant supernova explosions, allowing scientists to study these events and gain insights into stellar evolution and the life cycles of stars. So, by observing distant objects in space, we are essentially peering into the past and gaining knowledge about the history and evolution of the universe.