Space

January 10, 2013

NASA, ESA telescopes find evidence for asteroid belt around Vega

Astronomers have discovered what appears to be a large asteroid belt around the star Vega, the second brightest star in northern night skies. The scientists used data from NASA’s Spitzer Space Telescope and the European Space Agency’s Herschel Space Observatory, in which NASA plays an important role.

The discovery of an asteroid belt-like band of debris around Vega makes the star similar to another observed star called Fomalhaut. The data are consistent with both stars having inner, warm belts and outer, cool belts separated by a gap. This architecture is similar to the asteroid and Kuiper belts in our own solar system.

What is maintaining the gap between the warm and cool belts around Vega and Fomalhaut? The results strongly suggest the answer is multiple planets. Our solar system’s asteroid belt, which lies between Mars and Jupiter, is maintained by the gravity of the terrestrial planets and the giant planets, and the outer Kuiper belt is sculpted by the giant planets.

“Our findings echo recent results showing multiple-planet systems are common beyond our sun,” said Kate Su, an astronomer at the Steward Observatory at the University of Arizona. Su presented the results Tuesday at the American Astronomical Society meeting in Long Beach, Calif., and is lead author of a paper on the findings accepted for publication in the Astrophysical Journal.

Vega and Fomalhaut are similar in other ways. Both are about twice the mass of our sun and burn a hotter, bluer color in visible light. Both stars are relatively nearby at about 25 light-years away. The stars are thought to be around 400 million years old, but Vega could be closer to its 600 millionth birthday. Fomalhaut has a single candidate planet orbiting it, Fomalhaut b, which orbits at the inner edge of its cometary belt.

The Herschel and Spitzer telescopes detected infrared light emitted by warm and cold dust in discrete bands around Vega and Fomalhaut, discovering the new asteroid belt around Vega and confirming the existence of the other belts around both stars. Comets and the collisions of rocky chunks replenish the dust in these bands. The inner belts in these systems cannot be seen in visible light because the glare of their stars outshines them.

Both the inner and outer belts contain far more material than our own asteroid and Kuiper belts. The reason is twofold: the star systems are far younger than our own, which has had hundreds of millions more years to clean house, and the systems likely formed from an initially more massive cloud of gas and dust than our solar system.

The gap between the inner and outer debris belts for Vega and Fomalhaut also proportionally corresponds to the distance between our sun’s asteroid and Kuiper belts. This distance works out to a ratio of about 1:10, with the outer belt 10 times farther away from its host star than the inner belt. As for the large gap between the two belts, it is likely there are several undetected planets, Jupiter-sized or smaller, creating a dust-free zone between the two belts. A good comparison star system is HR 8799, which has four known planets that sweep up the space between two similar disks of debris.

“Overall, the large gap between the warm and the cold belts is a signpost that points to multiple planets likely orbiting around Vega and Fomalhaut,” said Su.

If unseen planets do in fact orbit Vega and Fomalhaut, these bodies will not likely stay hidden.

“Upcoming new facilities such as NASA’s James Webb Space Telescope should be able to find the planets,” said paper co-author Karl Stapelfeldt, chief of the Exoplanets and Stellar Astrophysics Laboratory at NASA’s Goddard Space Flight Center in Greenbelt, Md.

 




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


 
 

 

Headlines November 21, 2014

News: Dempsey lays groundwork for larger 2016 defense budget - The top U.S. military official on Wednesday made the case for growing the base defense budget significantly over the $535 billion spending cap imposed by Congress for fiscal 2015.   Business: Boeing can bill $61 million that Pentagon withheld for months - The Pentagon withheld $60.5 million...
 
 

News Briefs November 21, 2014

Obama aide: U.S. should look at Ukraine military aid A senior aide of President Barack Obama says he believes the U.S. should consider giving Ukraine lethal, defensive military assistance to get Russia to think twice about its destabilizing behavior. Tony Blinken, the deputy national security adviser, cites serious violations by Russia of agreements not to...
 
 
Air Force photograph by SrA. Divine Cox

Kunsan AB hosts Exercise Max Thunder 14-2

Air Force photograph by SrA. Divine Cox A South Korean air force F-15 Strike Eagle lands Nov. 17, 2014, during Max Thunder 14-2 at Kunsan Air Base, South Korea. U.S. Air Force, Army, Marine Corps and Navy personnel and aircraft...
 

 
LM-facility

Lockheed Martin opens Surface Navy Innovation Center

Lockheed Martin has opened the Surface Navy Innovation Center in Moorestown, N.J., to support the development of new technologies for the U.S. Navy. The SNIC is a research, development and demonstration facility that brings tog...
 
 
raytheon-test

Raytheon successfully demonstrates integrated electronic warfare capabilities

EL SEGUNDO, Calif. – Raytheon, in collaboration with the U.S. Navy, successfully demonstrated an end to end, first of its kind, integrated electronic attack system during flight tests at the Naval Air Weapons Station Chi...
 
 

Three bases identified as F-16 aggressor candidate bases

U.S. Air Force photo by Tech. Sgt. Joseph Swafford Jr. A U.S. Air Force F-16 Fighting Falcon fighter aircraft assigned to the 18th Aggressor Squadron lands at Eielson Air Force Base, Alaska, Oct. 6 during RED FLAG-Alaska 15-1. RF-A is a series of Pacific Air Forces commander-directed field training exercises for U.S. and partner nation...
 




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=""> <strike> <strong>