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Saturday, August 4, 2007

Planet Orbiting A Giant Red Star Discovered With Hobby-Eberly Telescope

Planet Orbiting A Giant Red Star Discovered With Hobby-Eberly Telescope

A planet orbiting a giant red star has been discovered by an astronomy team led by Penn State's Alex Wolszczan, who in 1992 discovered the first planets ever found outside our solar system.

The Hobby-Eberly Telescope, one of the largest and most powerful telescopes in the world, photographed at dusk by Penn State Astronomer Lawrence W. Ramsey, a leader in the conception, design, construction, and operation of the telescope. (Credit: Lawrence W. Ramsey, Penn State)

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The new discovery is helping astronomers to understand what will happen to the planets in our solar system when our Sun becomes a red-giant star, expanding so much that its surface will reach as far as Earth's orbit. The star is 2 times more massive and 10 times larger than the Sun. The new planet circles the giant star every 360 days and is located about 300 light years from Earth, in the constellation Perseus. A paper describing the discovery will be published in a November 2007 issue of the Astrophysical Journal.

The discovery resulted from an ongoing effort that the research team began three years ago to find Jupiter-mass planets around red-giant stars that are typically farther from Earth than those included in most other planet searches. "After astronomers have spent more than 10 years searching for planets around Sun-like stars and discovering over 250 planets elsewhere in our galactic neighborhood, we still do not know whether our solar system's properties, including life-supporting conditions on our planet, are typical or exceptional among solar systems throughout the Galaxy," Wolszczan says. "The picture for now, based on the searches for planets around stars like our Sun, is that our planetary system appears to be unusual in a number of ways."

The Hobby-Eberly Telescope, one of the largest and most powerful telescopes in the world, photographed at dusk by Penn State Astronomer Lawrence W. Ramsey, a leader in the conception, design, construction, and operation of the telescope.

"This planet is the first one discovered by Penn State astronomers with the Hobby-Eberly Telescope, and it is in one of the most distant of the ten published solar systems discovered around red-giant stars," comments Lawrence Ramsey, a member of the discovery team and the head of the Department of Astronomy and Astrophysics at Penn State. Ramsey is a leader in the conception, design, construction, and operation of the Hobby-Eberly Telescope. "We are now becoming serious participants in planetary searches and planetary astronomy using the Hobby-Eberly Telescope," he says.

Astronomers now are branching out with different strategies for searching for planets, with the hope of more quickly detecting life elsewhere in the universe, of discovering all the possible kinds of solar systems, and of learning how they form around different kinds of stars. Wolszczan's team used one of these new strategies -- searching for planets around giant stars, which have evolved to a later stage of life than our Sun's.

"We have compiled a catalog of nearly a thousand giant stars that are candidates for hosting solar systems," Wolszczan says. Because the method for discovering planets involves repeated measurements of their gravitational effect on the star they circle, and because planets around red giants can take years to make one orbit around the star, the research team is just now beginning to reap discoveries from years of systematic observations. "It took us 3 years to gather enough data on over 300 stars to start identifying those that are good candidates for having planetary companions," Wolszczan said. "This planet is just the first of a number of planet discoveries that this research program is likely to produce."

This research is a collaboration between astronomers at Penn State, Nicholas Copernicus University in Poland, the McDonald Observatory, and the California Institute of Technology. "One important aspect of this work is that it marks the debut of a research group in Poland, led by Dr. Andrzej Niedzielski, which has become a serious contributor to discoveries in extra-solar planetary astronomy," Wolszczan said.

One reason for studying solar systems that include red-giant stars is that they help astronomers to understand more about the future of our own solar system -- as family photos can give children an idea of what they might look like when they are the age of their grandparents. "Our Sun probably will make the Earth uninhabitable in about 2 billion years because it will get hotter and hotter as it evolves on its way to becoming a red giant about 5 billion years from now," Wolszczan says.

As the star swells up, transforming itself into a red giant, it affects the orbits of its planets and the dynamics of the whole planetary system, causing such changes as orbit crossings, planet collisions, and the formation of new planets out of the debris of those collisions. "When our Sun becomes a red giant, Earth and the other inner planets very likely will dive into it and disappear," Wolszczan says.

Another motivation for studying red-giant stars is to understand how their habitable zones move farther out as the star's radiating surface becomes bigger. Based on how long it took for life to develop on Earth, scientists speculate that there is more than enough time during a star's giant phase for life to get a start somewhere in the evolving habitable zones. "In our solar system, places like Europa -- a satellite of Jupiter that now is covered by a thick layer of water ice -- might warm up enough to support life for more than a billion years or so, over the time when our Sun begins to evolve into a red giant, making life on Earth impossible," Wolszczan said.

The Hobby-Eberly Telescope, one of the largest and most powerful telescopes in the world, photographed by Penn State Astronomer Lawrence W. Ramsey, a leader in the conception, design, construction, and operation of the telescope.

The method the astronomers use to discover planets is to observe candidate stars, repeatedly measuring their space velocity using the Doppler effect -- the changes in the star's light spectrum that result from its being pulled alternately toward and away from Earth by the gravity of an orbiting planet. "When we detect a significant difference in a star's velocity over a month or two, we then start observing that star more frequently," Wolszczan says. "In this paper, the velocity of the star changed by about 50 meters per second (about 100 miles per hour) between our first and second observations, so we observed that star more frequently and we found a clearly repeatable effect, indicating the presence of a planet."

A star and its orbiting planet move around the center-of-mass of the whole system, so the star alternately approaches and recedes from Earth periodically. "When the star gets closer to us, its light becomes a little bit bluer and when it recedes from us, its light becomes redder, and we can measure that effect to deduce the presence of planets," Wolszczan explains.

Searching for planets around giant stars also is a clever way to learn about the formation of planets around stars more massive than our Sun. Because massive stars are so hot when they are in the phase of life of our Sun, astronomers have not been able to detect enough of their spectral lines to use the Doppler-spectroscopy method of finding planets.

However, these stars become cooler as they evolve into giants, at which point the spectral-line observations needed for Doppler detection of planets become possible. "We want to know how often do planets form around stars that were more massive than our Sun," Wolszczan said. "Obviously, the more solar systems around red giants we discover and study, the better chance we have to really understand the big picture of planet formation."

Another reason astronomers are trying to discover planets around different kinds of stars at different stages of stellar evolution is to find out how different kinds of planetary systems change when their stars become red giants and how they ultimately end their lives as burnt-out, shrunken white-dwarfs.

"We really are at the very beginning of this effort and it is going to take time to get a consistent picture of planetary formation and evolution," Wolszczan says. "The more we learn, the greater the chance will be that sooner or later we will discover how ordinary or extraordinary is our home -- the Earth's solar system."

This research received financial support from NASA's Jet Propulsion Laboratory, Penn State's NASA-funded Astrobiology Program, the Polish Ministry of Science and Higher Education, and private donors.

Lenovo Targets Rural China With Basic PC

Lenovo Group Ltd. said Friday it will sell a basic personal computer aimed at China's vast but poor rural market and priced as low as $199.
Lenovo's announcement follows rival Dell Inc.'s bid to boost its presence in China's booming market with the unveiling in March of a low-cost personal computer meant for novice Chinese users

A Chinese sales clerk waits for customers as he works on Lenovo computers at a Lenovo shop in an electronics market in Beijing, in this Feb. 1, 2007 file photo. Lenovo Group Ltd., the world's No. 3 personal computer maker, reported a 12-fold jump in quarterly profits Thursday, Aug. 2, 2007, that beat market expectations as the Beijing-based company made progress in efforts to build a global brand. Profits were US$66.8 million (48.8 million) for the quarter ended June 30 on strong sales in China and the Americas, up from US$5.2 million (3.8 million) in the year-earlier period, the company said. (AP Photo/Elizabeth Dalziel, File)

Beijing-based Lenovo, which acquired IBM Corp.'s PC division in 2005, is expanding abroad but is eager to maintain its dominance in China, where research firm Gartner Inc. says PC sales grew by 23 percent last quarter.
"Our focus is to get down to the rural market," said company spokesman Jay Chen.
The new PC will use a buyer's television set as a monitor. Chen could provide no other details on the configuration or other features.
The new PC goes on sale later this year, and will range in price from $199 to $399.
Lenovo is the world's third-largest PC manufacturer, behind U.S.-based Hewlett-Packard co. and No. 2 Dell.
Dell, based in Round Rock, Texas, announced in March that it will sell a basic desktop PC designed for China and priced at $223 to $515.
Chen denied that Lenovo was responding to Dell's initiative. He said Lenovo has been selling a low-cost PC loaded with educational and other software meant for rural Chinese families since 2004.
"It's a natural evolution. We are not responding to our competitors," Chen said. "After three years of market development in low-tier markets we have gained experience and understanding."
Some 800 million people live in China's countryside, where incomes average about $560 a year but are rising at an annual rate of more than 10 percent.
Lenovo said it will set up a rural sales network of 5,000 dealers to reach farmers and other customers.
On Thursday, Lenovo reported a 12-fold jump in profits in the quarter ending June 30, with earnings of $66.8 million on revenues of $3.9 billion.

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Save Earth From Asteroid Strike

Former astronaut Rusty Schweickart has already earned his place in the history books by going to the moon with the Apollo 9 mission. However, should an asteroid crash into the Earth anytime soon, killing millions and causing catastrophic damage, he'll also be remembered as the guy whose warnings we ignored.

In 2001 Schweickart, now 71, helped found the B612 Foundation (named for the asteroid home in The Little Prince) to raise the alarm about the potential of death from above. The foundation has been loudly asking the world's space agencies to locate all the near-Earth asteroids, determine if any are likely to crash into us, and make plans to deflect them if necessary. But NASA and the other agencies have taken little action. Wired News spoke to Schweickart about the importance and frustrations of his latest mission.

Wired News: You've devoted the last six years to warning people about the catastrophic possibility of a near-Earth asteroid crashing into the Earth. Does this stuff keep you awake at night?

Rusty Schweickart: (laughs) Does it keep me up at night? Yes, but not in the way you're probably asking. I don't stay up at night worrying about an impact. I do stay up and work over in my mind various technical issues, and think about the work that needs to be done.

WN: When did you first start thinking about the threat posed by near-Earth asteroids?

Schweickart: My interest came from my prior interest in astrobiology, which is the research field looking at the origins and extent of life in the universe. When you look at the origins and evolution of life on Earth, it's been severely affected by asteroid impacts through history. I came to the clear understanding that this is not a historical process, or something that is no longer in effect. It's a continuing process, and we're continually vulnerable to, essentially, a control-alt-delete.

Life has sustained a number of those hard boots, to continue the metaphor, the demise of the dinosaurs 65 million years ago being only the most recent example that people are aware of. But there have been very damaging impacts far smaller than the one that occurred 65 million years ago, and they are far more frequent. Those are of more concern to humanity, but they're also predictable. If we know that something is going to happen and there's something we can do about it, we ought to start getting prepared.

WN: You were in the news a few years back talking about the asteroid 9942 Apophis, when it appeared there was a chance that it could hit the Earth in 2029 or 2036. That got some media attention, until further studies reduced the likelihood of impact to nearly zero. Were you relieved, or maybe a little disappointed that there was no urgent cause for action?

Schweickart: When the probability of impact in 2029 dropped to zero, I think everyone was very relieved. There is still to this day a possibility of impact in 2036. It is quite low, and it will most likely drop to zero. But Apophis has been a tremendous learning opportunity for the (near-Earth asteroid) community. It exemplifies the kind of challenge we will encounter in the future. There will be tens of thousands of near-Earth asteroids discovered in the next 10 to 20 years.

WN: The Planetary Society is still offering a $50,000 prize for the best plan to put a tracking device on Apophis when it swings by in 2029. Although it appears that will be unnecessary, do you think the design contest still serves a purpose?

Schweickart: In responding to that challenge, there are probably teams of people learning a great deal. The possibility of Apophis continuing to be a real threat is one in 45,000. But in terms of understanding the challenge that we're going to be facing with other near-Earth asteroids that we find -- and we will definitely find some that will be more threatening -- it's very useful.

The more people we have thinking seriously about this, the better. And I'm not talking about the general public wringing their hands, I mean technically qualified people seriously looking at the challenge of taking action. It's important to have people studying the orbital mechanics, the techniques we could use for deflection, and looking at the decision-making process that would be involved in deciding which asteroids to deflect. The legal and political implications will probably be the most difficult challenges.

WN: Why is that?

Schweickart: Who is it that makes the decision: Do we or do we not deflect this particular asteroid? Is it small enough that someone will say, "We'll just take this hit, we won't deflect this one"? If it's just going to impact a few counties, are they the only ones who pay for it? There are a million questions of that kind that will have to be answered, and not after we discover one that has our name on it, but before, so we don't end up in a decade-long debate when we're threatened.

About Rusty Schweickart

Russell Louis "Rusty" Schweickart (born October 25, 1935) is an American astronaut. Schweickart was born in Neptune, New Jersey. He earned an S.B. and an S.M. in Aeronautics/Astronautics from MIT in 1956 and 1963 respectively

Astronaut experience
Schweickart became an astronaut in October of 1963. He has spent over 241 hours in space on one spaceflight. In 1969, Schweickart served on the Apollo 9 mission during which he piloted the lunar module. This was the first manned test of the Apollo lunar module as well as the first broadcast of music from space. Schweickart was also due to perform an EVA, the first of the Apollo Programme that would test the Portable Life Support System that would be used to walk on the Moon.

Schweickart began to suffer from space sickness on the first day in orbit forcing the postponement of the EVA. Schweickart's condition was made worse as the mission Commander James McDivitt did not report it to Mission Control (the flight surgeon could have advised Schweikart on ways of limiting the effects). Eventually Schweickart improved and completed the EVA standing on the Lunar Module and provided an evocative description of the earth.

The space sickness contributed to Schweickart being sidelined for further Apollo missions and he concentrated on the Skylab programme.

Schweickart was awarded the NASA Distinguished Service Medal, and the NASA Exceptional Service Medal in 1973.

Rusty Schweickart has spoken and taught at the Esalen Institute. Schweickart is also cofounder of the B612 Foundation, a group that aims to defend Earth from asteroid impacts.

In the 1998 miniseries From the Earth to the Moon Schweickart was played by Kieran Mulroney.

In May 2005 Rusty Schweickart told the U.S. Congress that a mission to attach a device such as a radio transponder to asteroid 99942 Apophis (formerly known as 2004 MN4) should be a high priority; it is estimated that this asteroid has a 1 in 6000 probability of striking the earth in the 21st century[2]. The latest data indicates that the chance of Apophis impacting the earth is 1 in 45,000 in 2036.

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Taking Avandia? or not?

Now that the FDA has given the green light to allow a popular diabetes drug to stay on the market, many who take Avandia are wondering whether they should be taking it. Avandia is used by people with type two diabetes to control the amount of sugar or glucose the body puts out. And to help the body's insulin work more effectively. Since it went on the market in 1999, it's been used by about 6-million people in this country. But the FDA Advisory panel says there are certain diabetics who should definitely not take the drug. Those people include those who are prone to congestive heart failure or have already been diagnosed with the condition. People who are prone to heart attacks should also not be taking Avandia, according to the FDA's advisors. In addition, people who are long term insulin users have been found to be at higher risk for cardiovascular problems caused by the drug, as have people who are taking nitrates for chest pain or angina. Exactly how these warnings will be issued is still being worked out by the advisory panel, but at this point if you are taking Avandia and have a concern about the drug, the best advice is to talk with your doctor.

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