found that display a similar anomaly that is attributable to dust emission. As of 2002, about 400 of these stars have been found, and they have come to be termed "Vega-like" or "Vega-excess" stars. It is believed that these may provide clues to the origin of the Solar System. Debris disks By 2005, the Spitzer Space Telescope had produced high-resolution infrared images of the dust around Vega. It was shown to extend out to 43″ () at a wavelength of , 70″ () at and () at . These much wider disks were found to be circular and free of clumps, with dust particles ranging from 1– in size. The estimated total mass of this dust is 3 times the mass of the Earth (around 7.5 times more massive than the asteroid belt). Production of the dust would require collisions between asteroids in a population corresponding to the Kuiper Belt around the Sun. Thus the dust is more likely created by a debris disk around Vega, rather than from a protoplanetary disk as was earlier thought. The inner boundary of the debris disk was estimated at , or 70–. The disk of dust is produced as radiation pressure from Vega pushes debris from collisions of larger objects outward. However, continuous production of the amount of dust observed over the course of Vega's lifetime would require an enormous starting mass—estimated as hundreds of times the mass of Jupiter. Hence it is more likely to have been produced as the result of a relatively recent breakup of a moderate-sized (or larger) comet or asteroid, which then further fragmented as the result of collisions between the smaller components and other bodies. This dusty disk would be relatively young on the time scale of the star's age, and it will eventually be removed unless other collision events supply more dust. Observations, first with the Palomar Testbed Interferometer by David Ciardi and Gerard van Belle in 2001 and then later confirmed with the CHARA array at Mt. Wilson in 2006 and the Infrared Optical Telescope Array at Mt. Hopkins in 2011, revealed evidence for an inner dust band around Vega. Originating within of the star, this exozodiacal dust may be evidence of dynamical perturbations within the system. This may be caused by an intense bombardment of comets or meteors, and may be evidence for the existence of a planetary system. Possible planets Observations from the