An astronomer was recently in Delaware to talk about the state of the stars.
Mike Montgomery, a researcher at the University of Texas and astronomer with the McDonald Observatory, said some stars are constant in the universe, emitting the same amount of energy over time. Other stars pulsate.
“And that means that the amount of energy they radiate goes up and down a little bit in a kind of regular way,” Montgomery said.
Stellar pulsations are a relatively new area of study as they weren’t even measurable 30 years ago. Now, scientists use the pulsations to figure out what stars look like on the inside.
Montgomery said for example, scientists can learn about the interior composition of white dwarf stars, which are mostly composed of carbon and oxygen.
Scientists could use stellar pulsations to learn how fast stars are rotating, facts about their core and if the core is spinning faster than the surface layers.
The sun has about 4.5 billion years of its lifespan left.
Pulsations have even been helpful in adding to scientific knowledge about the sun. Montgomery said the sun pulsates thousands to millions of tiny little modes, or patterns, in various frequencies.
“As somebody put it, we actually know more about the center of the sun than we know about the center of the earth,” Montgomery said. “That’s because there’s so many oscillations. And on the earth, you don’t have very many. You just have earthquakes every now and then.”
What scientists also know about the sun, Montgomery said, is that it has about 4.5 billion years of its lifespan left.
That’s not an issue for the solar system and Earth now, but Delaware’s NASA ambassador Brandi Besecker said scientists know how to detect and measure if the sun is ready to give out.
“Sunlight takes eight-and-a-half minutes to get from the sun to Earth, so if something were to happen and we did not have sun observing satellites – which we do – we wouldn’t know for eight-and-a-half minutes…whatever had happened, we would see it eight-and-a-half minutes later,” she said.
Besecker said the slight delay is simply the time sunlight takes to travel to Earth at the speed of light.
The sun and other stars, Besecker said, are the mass and matter that make up the solar system. Without them, the galaxy wouldn’t be as beautiful and bright.
