U. S., European Space Observatories Identify Stars with Asteroid Belts

January 9th, 2013


Artist's illustration of recently discovered asteroid belt around the bright star Vega. Image Credit/NASA

Observations with NASA’s Spitzer space telescope and the European Space Agency’s Herschel Space Observatory have detected  familiar looking asteroid/cometary belts around Vega, a young star and one of the brightest objects in the northern night sky.

The band of small objects near Vega, separated by a gap, then followed by a second band of cooler objects appears similar to the lineup of planetary objects orbiting our own sun.

Our much older sun hosts the small inner rocky planets, the main asteroid belt, the larger gas planets and the Kuiper belt, a collection of comets. A second young star, Fomalhaut, appears to follow the same pattern. The gaps around Vega and Fomalhaut may be filled by young 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, in a NASA announcement.

Su presented the results gathered with Spitzer and Herschel on Tuesday at the American Astronomical Society meeting in Long Beach,Calif., and is the lead author of a paper on the findings accepted for publication in the Astrophysical Journal.

Vega and Fomalhaut weigh in at  twice the mass of our sun and burn a hotter, bluer color in visible light. They are relatively close to the Earth, about 25 light-years away.

While the sun is close to 5 billion years old, Vega is estimated at 600 million years, and Fomalhaut at 400 million years. A single planetary candidate has been discovered around Fomalhaut so far.

The findings suggest Vega and Fomalhaut are likely to be scrutinized closely in the future.

NASA’s James Webb Space Telescope, scheduled for launching in late 2018 as the successor to the Hubble Space Telescope, should be able to spot planets around Vega and Fomalhaut, ” according to  Karl Stapelfeldt, chief of the Exoplanets and Stellar Astrophysics Laboratory at NASA’s Goddard Space Flight Center, who co-authored the research paper presented in Santa Barbara.