University of Arizona | 2014 Nov 10
[c][attachment=0]HD95086.jpg[/attachment][/c]UA astronomers have discovered two dust belts surrounded by a large dust halo around young star HD 95086. The findings provide a look back at what our solar system may have resembled in its infancy.
[c][attachment=1]HR8799.jpg[/attachment][/c]
Scientists at the University of Arizona have discovered what might be the closest thing to "baby photos" of our solar system. A young star called HD 95086 is found to have two dust belts, analogous to the asteroid and Kuiper belts in the solar system, surrounded by a large dust halo that only young planetary systems have.
Similar dust structures also are found around another, slightly older star, HR 8799, where four massive planets occupy the large gap between the two belts. HR 8799, the first star found to host four directly imaged planets, is often referred to as a younger and scaled-up version of our solar system. Finding another star similar to HR 8799 suggests a common model for how stars form planets and how their planetary systems evolve.
The ages of these systems span an interesting period, about 10 million to 90 million years, when terrestrial planets form and giant planets settle down to their final configuration in our solar system, the team reports.
"We think HD 95086 is a snapshot of what our solar system might have looked like when it was only 10 million to 20 million years old," said Kate Su, an associate astronomer in the UA's Department of Astronomy and Steward Observatory and lead author of the paper.
Using data from NASA's Spitzer Space Telescope and ESA's Herschel Space Observatory combined with detailed simulations, the researchers found HD 95086 and HR 8799 each has a vast disk halo of fine dust, suggesting enhanced collisional activities in their Kuiper-belt-like belts. This is an expected behavior for systems that are experiencing dynamical settling of gas giants and possibly late formation of giant ice planets.
The large gap between the warm and cold belts in HD 95086, HR 8799 and some other nearby older systems such as debris disk twins Vega and Fomalhaut is an excellent signpost for multiple, yet-to-be-discovered planets, according to the research team.
HD 95086 and HR 8799 are located 295 and 129 light-years from earth in the constellations of Carina and Pegasus, respectively. ...
Follow the Dust to Find Planets
NASA | JPL-Caltech | Spitzer | 2014 Nov 10