Space

September 17, 2012

First planets found around sun-like stars in a cluster

NASA-funded astronomers have, for the first time, spotted planets orbiting sun-like stars in a crowded cluster of stars.

The findings offer the best evidence yet planets can sprout up in dense stellar environments. Although the newfound planets are not habitable, their skies would be starrier than what we see from Earth.

The starry-skied planets are two so-called hot Jupiters, which are massive, gaseous orbs that are boiling hot because they orbit tightly around their parent stars. Each hot Jupiter circles a different sun-like star in the Beehive Cluster, also called the Praesepe, a collection of roughly 1,000 stars that appear to be swarming around a common center.

The Beehive is an open cluster, or a grouping of stars born at about the same time and out of the same giant cloud of material. As such, the stars share a similar chemical composition. Unlike the majority of stars, which spread out shortly after birth, these young stars remain loosely bound together by mutual gravitational attraction.

“We are detecting more and more planets that can thrive in diverse and extreme environments like these nearby clusters,” said Mario R. Perez, the NASA astrophysics program scientist in the Origins of Solar Systems Program. “Our galaxy contains more than 1,000 of these open clusters, which potentially can present the physical conditions for harboring many more of these giant planets.”

The two new Beehive planets are called Pr0201b and Pr0211b. The star’s name followed by a “b” is the standard naming convention for planets.

“These are the first ‘b’s’ in the Beehive,” said Sam Quinn, a graduate student in astronomy at Georgia State University in Atlanta and the lead author of the paper describing the results, which was published in the Astrophysical Journal Letters.

Quinn and his team, in collaboration with David Latham at the Harvard-Smithsonian Center for Astrophysics, discovered the planets by using the 1.5-meter Tillinghast telescope at the Smithsonian Astrophysical Observatory’s Fred Lawrence Whipple Observatory in Arizona to measure the slight gravitational wobble the orbiting planets induce upon their host stars. Previous searches of clusters had turned up two planets around massive stars but none had been found around stars like our sun until now.

“This has been a big puzzle for planet hunters,” Quinn said. “We know that most stars form in clustered environments like the Orion nebula, so unless this dense environment inhibits planet formation, at least some sun-like stars in open clusters should have planets. Now, we finally know they are indeed there.”

The results also are of interest to theorists who are trying to understand how hot Jupiters wind up so close to their stars. Most theories contend these blistering worlds start out much cooler and farther from their stars before migrating inward.

“The relatively young age of the Beehive cluster makes these planets among the youngest known,” said Russel White, the principal investigator on the NASA Origins of Solar Systems grant that funded this study. “And that’s important because it sets a constraint on how quickly giant planets migrate inward. And knowing how quickly they migrate is the first step to figuring out how they migrate.”

The research team suspects planets were turned up in the Beehive cluster because it is rich in metals. Stars in the Beehive have more heavy elements such as iron than the sun has.

According to White, “Searches for planets around nearby stars suggest that these metals act like a ‘planet fertilizer,’ leading to an abundant crop of gas-giant planets. Our results suggest this may be true in clusters as well.”

NASA’s Jet Propulsion Laboratory, Pasadena, Calif., manages NASA’s Exoplanet Exploration Program office.

 




All of this week's top headlines to your email every Friday.


 
 

 
Lockheed Martin photograph

Fourth Lockheed Martin-built MUOS secure comm satellite shipped

Lockheed Martin photograph On June 28, MUOS-4, the next satellite scheduled to join the U.S. Navy’s Mobile User Objective System secure communications network, shipped to Cape Canaveral from Lockheed Martin’s satellite manu...
 
 
Photograph courtesy of NASA/CXC/U. Wisconsin/S. Heinz

NASA’s Chandra captures x-ray echoes pinpointing distant neutron star

Photograph courtesy of NASA/CXC/U. Wisconsin/S. Heinz A light echo in X-rays detected by NASA’s Chandra X-ray Observatory has provided a rare opportunity to precisely measure the distance to an object on the other side of the...
 
 

Veteran NASA spacecraft nears 60,000th lap around Mars

NASA’s Mars Odyssey spacecraft will reach a major milestone June 23, when it completes its 60,000th orbit since arriving at the Red Planet in 2001. Named after the bestselling novel “2001: A Space Odyssey” by Arthur C. Clarke, Odyssey began orbiting Mars almost 14 years ago, on Oct. 23, 2001. On Dec. 15, 2010, it...
 

 
nasa-study

NASA selects six wild ideas in aviation for further study

NASA has selected six proposals to study transformative ideas that might expand what’s possible in aviation, shifting the boundary between fantastic and futuristic. During a day-long meeting in April, 17 teams pitched the...
 
 
NASA photograph

NASA signs agreement with Space Florida to operate historic landing facility

NASA photograph This aerial photo of the runway at the KSC Shuttle Landing Facility looks north. Longer and wider than most commercial runways, it is 15,000 feet long, with 1,000-foot paved overruns on each end, and 300 feet wi...
 
 

All systems go for NASA’s mission to Jupiter moon Europa

Beyond Earth, Jupiter’s moon Europa is considered one of the most promising places in the solar system to search for signs of present-day life, and a new NASA mission to explore this potential is moving forward from concept review to development. NASA’s mission concept — to conduct a detailed survey of Europa and investigate its...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>