WPBT2's Star Gazers

Episode #11-41 "The Secret Lives Of Stars"
Air Dates October 10-16, 2011

DEAN: Welcome to Star Gazers. I’m Dean Regas, Outreach Astronomer from The Cincinnati Observatory.

JAMES: And I’m James Albury, Director of the Kika Silva Pla Planetarium in Gainesville, Florida.

DEAN: Stars are not always what they seem. Most stars in the sky are really two, three, or more stars orbiting each other. Many stars wildly fluctuate in brightness. They’re all different colors and temperatures. Some are newly born and others are nearing their dramatic demise.

JAMES: This week we’re going to look at three stars in the Fall sky with hidden secrets. The first star is really two beautifully colored stars in a small telescope.

DEAN: The second will make your head spin.

JAMES: And the third is a lonely star with a funny name that gave astronomers a big planetary surprise. As our telescopes get better and better we’re uncovering the mysterious nature of stars trillions of miles away. Let us introduce you to the stars Albireo, Altair and Fomalhaut.

JAMES: Okay, we have our skies set to 10:00 p.m. this month looking West. The most prominent feature in this part of the sky is the Summer Triangle. Look for the three brightest stars in the sky and you’ve found it.

DEAN: The three stars are called Vega…, Altair… and Deneb.

JAMES: Now Deneb is supposed to be the bright tail of the constellation Cygnus the Swan but we’re going to zoom in on the fainter head star visible inside the Summer Triangle. This is the star called Albireo and it’s one of the favorites for amateur astronomers with a small telescope.

DEAN: When you look closer at Albireo, you find it’s really a double star – two stars orbiting each other. The bigger one is orange in color and the smaller one is brilliant blue. The contrasting colors make a cool and hot sight to see – because this tells us their contrasting temperatures. The bluer, the hotter. The oranger, the cooler. They’re like two beautiful jewels in the night sky.

JAMES: Now let’s get back to the star Altair and his hidden secret. Altair looks like any ordinary bright white star. But Altair is one of the closer stars to us at only 17 light years away.

DEAN: And because it’s relatively close, astronomers could uncover Altair’s secret – its mind-boggling rotational rate.

JAMES: Meaning it spins really fast!

DEAN: Our Sun spins as well. The Sun rotates about 2 kilometers per second at its equator so it takes about 25 days for the Sun to spin once at the equator. Now let’s compare our Sun to Altair. Altair is almost twice as big as the Sun and shines 11 times brighter. But hold onto your seats, this star spins super-fast! At the equator, Altair rotates at about 286 kilometers per second. That means that the entire star spins once every 9 hours!

JAMES: This unbelievable rotational velocity has actually affected the shape of this star. Instead of a sphere, Altair is squished at the poles and bulges at the equator. The entire mass of the star has shifted and has left Altair looking like a rapidly spinning egg-shaped star.

DEAN: Next, let’s look South at 10:00 p.m. where you’ll see only one bright star. This is Fomalhaut the brightest star in the constellation of Piscis Australis or the Southern Fish.

JAMES: With a little imagination you can make out a goldfish shape in these stars with Fomalhaut as one beady eye.

DEAN: Fomalhaut is a blue-white star 25 light years away, making it another close target to observe with the best telescopes. In 2004 astronomers detected a dust ring around Fomalhaut.

JAMES: We call it proto-planetary debris.

DEAN: Or just a big ring of stuff and… everyone got excited. This was the kind of proto-planetary debris that might harbor a planet or even a whole solar system.

JAMES: And then in 2008, astronomers caught the first visible-light image of a planet orbiting around another star. Orbiting around Fomalhaut. You have to really squint, but there it is. So check out Fomalhaut tonight, the lone star in the South.

DEAN: That’s not so lonely after all.

JAMES: Find rapidly rotating Altair in the Western sky on the left side of the Summer Triangle.

DEAN: And don’t forget to train your telescopes on Albireo to discover its second sun. When you look at the stars above who knows what other hidden secrets you’ll discover when you…

BOTH: Keep looking up!


Episode #11-41 M "The Secret Lives Of Stars"
Air Dates October 10-16, 2011

DEAN: This month at 10:00 p.m. look for the Summer Triangle high in the West. These are three bright stars, Deneb, Vega, and Altair.

JAMES: At only 17 light years away, Altair is one of our closest stars and although Altair looks like a normal white star it has a hidden secret.

DEAN: Altair spins at over 286 kilometers per second! That spinning is so fast that it actually squishes the entire star at the poles! When you look South at 10:00 p.m. you’ll see only one bright star. This is Fomalhaut the brightest star in the constellation of Piscis Australis or the Southern Fish.

JAMES: Astronomers photographed the first ever planet around Fomalhaut. You have to really squint, but there it is. Astronomers have discovered hundreds of planets around other stars but this is the only picture of one. When you look at the stars above, who knows how many of them have planets….

DEAN: And which spin like crazy.

BOTH: Keep looking up!


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