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.


 
 

 
NASA, ESA, PSI, JHU/APL, STScI/AURA image

Close encounters: Comet Siding Spring seen next to Mars

NASA, ESA, PSI, JHU/APL, STScI/AURA image This composite NASA Hubble Space Telescope Image captures the positions of comet Siding Spring and Mars in a never-before-seen close passage of a comet by the Red Planet, which happened...
 
 

NASA Astronaut Scott Kelly shares bullying prevention message ahead of one-year mission

NASA astronaut Scott Kelly, who is scheduled to fly on a one-year spaceflight mission in 2015, is lending his voice to help reduce childhood bullying. As part of Bullying Prevention Awareness Month, Kelly recorded a special message encouraging bystanders to take action. “Be more than just a bystander,” said Kelly in the message. “Take action...
 
 

NASA seeks ultra-lightweight materials to help enable journey to Mars

NASA is seeking proposals to develop and manufacture ultra-lightweight materials for aerospace vehicles and structures of the future. Proposals will demonstrate lower-mass alternatives to honeycomb or foam cores currently used in composite sandwich structures. Composite sandwich structures are a special type of material made by attaching two thin skins to a lightweight core. This type...
 

 

Boeing concludes commercial crew space act agreement for CST-100/Atlas V

Boeing has successfully completed the final milestone of its Commercial Crew Integrated Capability Space Act Agreement with NASA. The work and testing completed under the agreement resulted in significant maturation of Boeing’s crew transportation system, including the CST-100 spacecraft and Atlas V rocket. NASA in July approved the Critical Design Review Board milestone for Boeing’...
 
 

NASA partners with leading technology innovators to enable future exploration

Recognizing that technology drives exploration, NASA has selected four teams of agency technologists for participation in the Early Career Initiative pilot program. The program encourages creativity and innovation among early career NASA technologists by engaging them in hands-on technology development opportunities needed for future missions. NASA’s Space Technology Mission Directorate c...
 
 

New commercial rocket descent data may help NASA with future Mars landings

NASA successfully captured thermal images of a SpaceX Falcon 9 rocket on its descent after it launched in September from Cape Canaveral Air Force Station, Fla. The data from these thermal images may provide critical engineering information for future missions to the surface of Mars. “Because the technologies required to land large payloads on Mars...
 




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>