For those of you in the U.S. Happy Labor Day!
I tell my audiences that stars are like people. They come in all sizes and colors, they are born, they produce "offspring" in the form of planets, they live, they die.
Doctors have used twins to study human health because you can learn a lot from following the course of the lives of each of them to see how they age, what happens to them and then apply that knowledge to other humans.
Astronomers do the same thing in their study of stars. They are classified according to their masses relative to our own Sun which determines their temperature, color, longevity and manner of death. They also search for stars that are identical to our star, the Sun, so they can learn more about the Sun.
It was recently announced that a solar twin had been discovered that is 8.2 billion years old as compared to our Sun's age of 4.6 billion years. HIP 102152 is in the constellation Capricornus and is 250 light years away. The youngest solar twin is 18 Sco located in the constellation Scorpius and is 2.9 billion years old.
Having two solar twins at younger and older ages provides a backdrop to our Sun that astronomers can use to interpret what is going on in our Sun now and what will occur in the distant future.
The Sun will continue to shine for about 5 billion more years and then will begin to end its life. It will swell to about 100 million miles - possibly engulfing the Earth but definitely ending all life as the oceans and atmosphere will boil away and the surface likely will become molten. The Sun will become a vast shell of gas and dust, called a planetary nebula, puffing away the majority of its outer layers to reveal its dead core - a white dwarf star.
Read More About It: http://www.eso.org/public/news/eso1337/
Sky Guy in VA