The 1997 movie “Contact,” based on Carl Sagan’s novel, follows the story of scientist Ellie Arroway as she travels through a wormhole to the star Vega. Recent research by astronomers at the University of Arizona, Tucson, using NASA’s Hubble and James Webb space telescopes, has provided new insights into the nearly 100-billion-mile debris disk surrounding Vega. The disk is described as “ridiculously smooth” and lacks evidence of large planets moving through it. This discovery challenges existing models of exoplanet systems and sheds light on the diversity of circumstellar disks.
The infrared glow from the tiny particles swirling around Vega has been captured by the Webb telescope, while the Hubble telescope has revealed an outer halo of the disk made up of smoke-like particles reflecting starlight. The distribution of dust in the Vega debris disk is layered due to the pressure of starlight pushing out smaller grains faster than larger ones. These new observations are helping researchers understand the dynamics of circumstellar disks and are providing valuable insights into the planet-formation process.
The Vega system’s smooth disk, with a subtle gap around 60 AU from the star, suggests the absence of large Neptune-sized planets in wide orbits similar to our solar system. This discovery highlights the variety among circumstellar disks and their connection to underlying planetary systems. Despite the lack of clear evidence for hidden planets, astronomers are learning more about planet formation and are using these new observations to refine their models.
Stars like Vega have dusty disks enriched by ongoing collisions among orbiting debris from comets and asteroids. The architecture of the Vega system is markedly different from our own solar system, where giant planets play a role in shaping the dust distribution. By comparing Vega to a nearby star like Fomalhaut, which has three nested debris belts possibly shaped by shepherding planets, researchers are trying to understand the factors influencing planetary formation and disk morphology.
Vega, located in the constellation Lyra, is one of the brightest stars in the northern sky and has been a subject of interest for centuries. The first evidence of material orbiting a star, potentially forming planets, was observed in 1984. Recent observations using the Hubble and Webb telescopes have provided detailed insights into the Vega system that were previously unknown. These findings offer valuable clues about the planet-formation process and the diversity of circumstellar disks, opening up new avenues for research in the field of exoplanet studies.