First planets found around sun-like stars in a cluster

Sep 14, 2012
Praesepe: the open cluster Messier 44. Credit: NASA

(Phys.org)—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 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 . 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 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 .

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 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 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 suggest that these metals act like a 'planet fertilizer,' leading to an abundant crop of gas-. Our results suggest this may be true in clusters as well."

Explore further: How baryon acoustic oscillation reveals the expansion of the universe

Related Stories

Two 'b''s in the Beehive

Aug 15, 2012

As astronomers near the 800 mark for confirmed extra solar planets, it seems that notable milestones are becoming fewer and further between. Multi-planet systems aren’t even worth mentioning. Planets ...

Some stars capture rogue planets

Apr 17, 2012

(Phys.org) -- New research suggests that billions of stars in our galaxy have captured rogue planets that once roamed interstellar space. The nomad worlds, which were kicked out of the star systems in which ...

Planets Living on the Edge

Dec 17, 2008

(PhysOrg.com) -- Some stars have it tough when it comes to raising planets. A new image from NASA's Spitzer Space Telescope shows one unlucky lot of stars, born into a dangerous neighborhood. The stars themselves ...

Baby Jupiters must gain weight fast

Jan 05, 2009

The planet Jupiter gained weight in a hurry during its infancy. It had to, since the material from which it formed probably disappeared in just a few million years, according to a new study of planet formation ...

Image: The Milky Way's 100 billion planets

Apr 26, 2012

(Phys.org) -- This artist's illustration gives an impression of how common planets are around the stars in the Milky Way. The planets, their orbits and their host stars are all vastly magnified compared to ...

Recommended for you

The Great Cold Spot in the cosmic microwave background

9 hours ago

The cosmic microwave background (CMB) is the thermal afterglow of the primordial fireball we call the big bang. One of the striking features of the CMB is how remarkably uniform it is. Still, there are some ...

Mystery of rare five-hour space explosion explained

Sep 17, 2014

Next week in St. Petersburg, Russia, scientists on an international team that includes Penn State University astronomers will present a paper that provides a simple explanation for mysterious ultra-long gamma-ray ...

User comments : 4

Adjust slider to filter visible comments by rank

Display comments: newest first

kevinrtrs
1 / 5 (11) Sep 16, 2012
We know that most stars FORM in clustered environments like the Orion nebula,

One should point out the obvious obfuscation here: The sentence should really read "..most stars are found in..." and the word "form" should be deleted or disregarded completely.
IN true scientific manner, one should admit that there is absolutely zero observational support for planets "forming" anywhere.
This is simply the dogmatic and religious hangover from a philosophical wish. Right now, in real, tangible observational evidence, there is no case whatsoever of a report of planetary formation anywhere.
One really needs to be on the lookout for such disinformative statements as is sprouted everywhere in cosmology/astronomy these days.
Stars and planets have not been observed to form anywhere in any shape or form. So scientists really have no right to speak of things that exist already as having "formed" there. There just is no observational evidence to support such statements. Period.
kevinrtrs
1 / 5 (11) Sep 16, 2012
"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."

This is a truly nonsensical statement if ever there was one. What the researcher should really say is that "it has been observed that there is a high frequency of occurrence of planets in orbits around iron/heavy metal rich stars". Thus going by such frequency, one can make an assumption that it will be profitable to look for more planets around stars which are known to be heavy-metal rich. The nonsense that the quote shows is that somehow planets "grow" up around heavy-metal-rich stars.
This is unscientific/pseudo science since no observational evidence exist to show that planets "grow" from clouds of dust to the large spheres they are today. AS yet it needs to be conclusively demonstrated via observational evidence that planets and stars grow up out of clouds of dust.
jsdarkdestruction
1 / 5 (1) Sep 16, 2012
kevin, please kindly fuck off. go read your bible and talk to your church buddies and leave the grown ups doing science alone.
aroc91
not rated yet Sep 17, 2012
Do your job, moderators.