Astronomers found another planet? (Yawn)

By Jeanna Bryner

updated 2:52 p.m. ET June 11, 2007

Alien worlds, once hidden from knowledge, are now being discovered in droves, stunning astronomers with their unique features and sheer numbers. The discoveries are so common that more and more don't even get reported outside scientific circles.

Take the announcement at the end of May of a massive planet, dubbed TrES-3, that zips around its star in an amazingly rapid 31 hours, giving the planet a 1.3-day year. Astronomers issued a press release, but you might not have heard about it because the discovery was so overshadowed by other planet announcements and barely received news coverage.

"It's pretty routine now," said Alan Boss, a planet formation theorist at the Carnegie Institution of Washington. "Most planets that are found are not deemed worthy of a press release because they are sort of becoming 'one more planet.'"

The total is now more than 200 extrasolar planets confirmed. And this is the tip of the iceberg in planet finds. Astronomers have more tools than ever, and technology is so advanced that planet discovery has become almost mundane.

The regularity of planet finds, luckily, is buffered by the wild variety in the discoveries themselves, including the following contrasts: nascent worlds of just a million years versus those that are billions of years old; hot gas giants and icy Neptune-like orbs; planets that whip around their parent stars with cosmic speed and others that seem to creep at a slug's pace; and planets orbiting double-stars, red-dwarf stars and even so-called failed stars.

Transit technique
Astronomers spotted TrES-3 as part of the Trans-atlantic Exoplanet Survey while looking for transiting planets, or those that pass directly in front of their home star with respect to Earth. It was detected with a network of telescopes in Arizona, California and the Canary Islands. When TrES-3 coasted in front of its home star, the telescopes picked up a slight dimming of the star's light, by about 2.5 percent. The scientists used the dimming to estimate the planet's mass, size and other properties.

Slideshow   From Earth to stars Catch a blast from the sun, a clash between galaxies and other outer-space highlights from October. more photos

It is located 800 light-years away in the constellation Hercules about 10 degrees west of Vega, one of the brightest stars in the summer skies of the northern hemisphere.

"It is also a very massive planet-about twice the mass of the solar system's biggest planet, Jupiter-and is one of the planets with the shortest known periods," said a co-discoverer of TrES-3 Georgi Mandushev of the Lowell Observatory in Arizona.

The giant orb orbits so close to its parent star, about 50 times closer than Earth is to the Sun, the astronomers estimate its temperature soars to about 1,500 degrees Kelvin.

Stellar wobbles
While the "transit method" provides astronomers with the best indirect information about an exoplanet, so far only about 20 transiting planets have been spotted.

That's why the most successful (based on the number of planet finds) teams have relied on the so-called wobble method, or radio-velocity technique.

"The radial-velocity teams are the most successful," Boss told SPACE.com. "They are a victim of their own success. They are able to get more and more telescope time, because they can prove to the assignment committees that give out the time that 'if you give us so many more nights we can probably find you so many more planets,'" Boss said.

He added, "The key bottleneck for finding more planets is simply more time on a telescope."

MORE FROM SPACE

Space Section Front

Space shuttle Atlantis fueled up for launch Geeky ‘tweeters’ to report on shuttle launch Atlantis’ team carries the ball for NASA Get the most from a promising meteor show Water discovery fuels hope to colonize moon ‘Significant amount’ of water found on moon World not ending in 2012, says NASA Cosmic Log: Marvelous view ... and a mystery Broken urine recycler may affect space mission   Month in space: What a blast! Space Section Front   Add Space headlines to your news reader: