Unseen planets sweep up dust around young star

TUCSON, Ariz. — The layout of the solar system might not be unique. New observations of a young star show similarities to what our solar system might have looked like after the planets formed 4.6 billion years ago.

Astronomer Kate Su and planetary scientist Sarah Morrison, both of the University of Arizona, and colleagues discovered a roughly 10-billion-kilometer-wide gap in the dusty disk encircling HD 95086, a 20-million-year old star about 295 light-years away in the constellation Carina. The gap, revealed in data from the Spitzer and Herschel space telescopes, divides the disk into two regions: an inner ring analogous to our asteroid belt and an outer ring similar to the Kuiper belt, the icy debris field just past Neptune.

Su and Morrison, speaking November 11 at the American Astronomical Society’s Division for Planetary Sciences meeting, say that HD 95086 hints at a common path followed by many growing planetary systems.

Young planets can carve out gaps in disks, but the one known planet orbiting HD 95086 couldn’t make one this big. Morrison says that several additional planets are needed, which would make HD 95086 similar to the slightly older HR 8799 (SN: 12/6/08, p. 5). Both have inner and outer belts that enclose several giant planets, resembling a larger, more massive version of our solar system.