There's a little bit of a star in all of us
Everybody is a star. Remember that Sly and the Family Stone hit of the same name? Well, it's actually true.
Each and every one of us has a little bit of the stuff stars are made of within us. If you have iron in your blood or calcium in your bones, you have star stuff in you. Even the gold and silver in your wedding ring was part of a star eons ago. In fact, all heavy elements in our universe are exclusively the result of supernovas, giant stellar explosions that bring a cataclysmic end to super massive stars. Astronomers and other scientists agree supernova explosions are the only way heavy materials like gold, silver and uranium can physically form.
When a star begins to run out of hydrogen fuel in its core, it swells out, becoming a red giant star many, many times larger than its original size. The details about how all this plays out get a little hairy, but basically, here's what happens.
Through the course of a star's life, hydrogen atoms fuse into heavier helium atoms inside the core of a star. This is called nuclear fusion. When the hydrogen inside the stellar core is exhausted and there's nothing left but helium atoms, the helium core then begins to collapse because of gravity. This produces a tremendous amount of heat that fires up runaway nuclear fusion in the outer layers of the star. This results in the entire star bloating out into a red giant.
This will happen to our sun in about 4½ to 5 billion years, and when it does, our sun will balloon out so far it will swallow up the first two planets. Say goodbye to Mercury and Venus! Don't feel too safe on Earth, though, because the sun's bloated outer edge will be close enough to the Earth to boil away the oceans. Needless to say, we'll fry in the ultimate case of global warming, but again, don't wait up for this because it won't happen for another 4½ to 5 billion years.
An average star like our sun remains a red giant for about 1 billion years as it totally runs out of nuclear fuel. When that happens, the red giant star can no longer support itself and begins to gravitationally collapse into a white dwarf star, not much larger than our 8,000-mile-wide Earth. It becomes a retired star that eventually flickers out completely.
More massive stars, about eight times more massive, meet a much more violent end. These stars go through normal lifetimes and become super huge red giant stars. One example of a super red giant in our night sky right now is Betelgeuse, the second brightest star in the great constellation Orion the Hunter, which is now adorning the southeastern Butler evening skies. It marks the armpit of Orion.
Betelgeuse is a huge star that beats like a gargantuan heart. Even at its minimum, Betelgeuse's diameter is about 400 million miles, but it regularly balloons out to 1 billion miles in girth! When you gaze at Betelgeuse I can tell you confidently you're looking at the biggest single thing you've ever seen.
No one knows for sure, but sometime within in the next million years — or maybe even just a few thousand years — Betelgeuse will exponentially explode beyond biblical proportions in what astronomers call a supernova.Supernovas are triggered as super giant red stars like Betelgeuse develop iron cores as they lose their ability to produce energy through nuclear fusion. Again, the details get really hairy, too hairy to get into here, but as the behemoth star begins to gravitationally collapse on itself and onto that iron core, it becomes explosively unstable.At that point, it's annihilation time! The star explodes, and the stellar shrapnel flings out in all directions at speeds of more than 10,000 miles per second! The heat of this explosion "cooks" up heavier elements like gold, silver and uranium. This "cooking" process is more formally known as nuclear synthesis.Materials including heavy elements spread out so far in all directions they end up seeding surrounding clouds of developing star clusters and solar systems. Our own solar system was laced with heavy elements from a supernova from who knows where, billions and billions of years ago. Stellar shrapnel like iron and calcium even wind up in our bodies!It's been a long time since we've had a major supernova explosion in our part of the Milky Way galaxy. The last major one was in 1054. It was so bright, for a few weeks, it was even visible in the daytime sky. Nearly 1,000 years after this big blast, the remnants are still visible but much fainter. It's called the Crab Nebula, and it's next to one of the horns of the constellation Taurus the Bull as you can see in the diagram. Scan that part of the sky with a small to moderate telescope and see if you can spot the faint little patch of light that once was a mighty star 39,000 trillion miles away.By the way, if you're worried about Betelgeuse exploding and what it would do to the Earth, don't. Most astronomers think it's far enough away at more than 600 light-years the gamma ray burst that would toast life on Earth will go off in a different direction from our worldly home.Just remember, you have stellar stuff in you!<B><I>Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and is author of the book, "Pennsylvania Starwatch," available at bookstores and at his Web site www.lynchandthestars.com.</I></B>
