Tuesday, August 07, 2007

Latest Exo-Planets: Super-huge, Have Water

Meet TrES-5, a gas-giant in the constellation of Hercules about 1,435 light years away. It circles a star with the unfortunate name of GSC02620-00648. This is no ordinary gas-giant. First of all, it’s 70 percent larger than Jupiter, qualifying it as “the largest known exoplanet,” but surprisingly, it’s not the heaviest. This according to a report at the BBC.

Although it’s much larger than Jupiter, TrES-5 weighs less.

How is this possible? Wouldn’t such low density make TrES-5 a cloud? Well, according to the International Astronomical Union’s definition of a planet (
more on that here), TrES-5 may qualify as a planet because it orbits a star and it has enough mass to be round.

But there’s a third requirement TrES-5 may have trouble with. In order to officially achieve planetary status, a celestial body must dominate its orbit by clearing out all the smaller debris (in other words, it must “clear the neighborhood”). Because of its low density, Tres-5’s upper atmosphere “probably escapes in a curved comet-like tail.” Doesn’t that sound incredibly awesome, beautiful?

I wonder if TrES-5’s week gravity makes it hard to “clear the neighborhood.”

Another recent exoplanet discovery is the second confirming the existence of water outside of our solar system. This planet, called HD 189733b, circles a star in the Culpecula system about 64 light years from Earth. While water is present, there’s not much chance of life here. “Although water is a key ingredient for biology, the planet is far too hot to harbour life,”
reports the BBC. HD 189733b orbits so close to its star, 30-times closer than the Earth to the Sun, that temperatures soar up to 1,700 degrees Fahrenheit.

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I started pound360 to channel my obsession with vitamins, running and the five senses. Eventually, I got bored focusing on all that stuff, so I came back from a one month hiatus in May of 2007 (one year after launching Pound360) and broadened my mumblings here to include all science.