If astronomers’ hunches about a recently discovered asteroid belt are correct, one of the brightest stars in our sky may support its own collection of planets.
Using NASA’s Spitzer Space Telescope and ESA’s Herschel Space Observatory, astronomers have discovered a giant asteroid belt around Vega. The fifth-biggest star in the sky, Vega is a larger and younger star than our own solar system’s bright center by leaps and bounds; Vega boasts twice the mass of our sun, and at 600 million years old, it’s also 3.4 billion years younger. With such a large center, the rest of the system is equally massive: the Vega system is 4-times the size of our solar system.
“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.
While the differences between our system and the Vega system are immense, the similarities are really what have astronomers intrigued: our structural similarity may mean exoplanets, planets beyond our solar system, may soon be discovered. With this new asteroid belt spotted by telescopes that see in infrared light, the image of the Vega system appears much more similar to our own.
When adjusted to a similar scale, both solar systems have a warmer, inner asteroid belt (the one between Mars and Jupiter) and a cooler, outer asteroid belt at the edges. A younger, dustier system, if the Vega system does have planets, they seem likely to be hidden between these two asteroid belts.
In addition to our sun, Vega recalls the observed star Fomalhaut. Younger than Vega, but approximately the same size, Fomalhaut also has two asteroid belts surrounding it–with a large planet dubbed “Fomalhaut b” nestled in between. With its size and dual-belted structure, Fomalhaut is also believed to support additional planets.
The discovery of this asteroid belt could lead to a much larger finding of planets orbiting Vega itself. By 2018, astronomers may know with more certainty whether there are more planets around Fomalhaut and any planets orbiting Vega. The James Webb Space Telescope will launch that year, ready to trace the weak infrared light from both systems.