I had a very interesting conversation with the first and second graders over at Sunset Valley Elementary School yesterday. After taking a virtual trip around the universe, a student named Ella brought up the subject of stars. She wondered if red stars were dying. Then Matthew pointed out that blue stars were the hottest. These students raised very important points, because it turns out that a star’s color tells us a lot about them, including their temperature, age, and size.
So Ella, the answer to your question is yes — and no. Some stars are red because they are small and don’t get very hot. They burn coolly and much more slowly than the bigger, faster burning yellow, white, and blue stars. These red stars are not dying (at least not for a very long time). However, bigger (more massive) stars sometimes turn into ‘red giants’ near the end of their lives. In fact, that may be exactly what happens to our sun about 5 billion years from now. To see how that might happen watch this NASA/ESA video on the The Death of Stars.
But stars were not all that the Sunset Valley students were talking about. They know about the Milky Way, supernovae, the planets in our solar system, and most of them can tell the difference between the near side and the far side of the moon! Amazing, right? I’d say the night sky isn’t the only place to find ‘luminous bodies’ in Austin, Texas. The first and second grade classes over at Sunset Valley are brimming with bright young stars!