[LINK] "Pluto-like Objects Turn to Dust Around a Nearby Young Star"

[rfmcdonald]

Universe Today's Shannon Hale writes about a newly-discovered disk of debris orbiting HD 107146, a very young star apart from its age quite like the Sun.

A planetary system’s early days readily tell of turmoil. Giant planets are swept from distant birthplaces into sizzling orbits close to their host star. Others are blasted away from their star into the darkness of space. And smaller bodies, like asteroids and comets, are being traded around constantly.

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have seen the latter: swarms of Pluto-size objects turning to dust around a young star. And the image is remarkable.

“This system offers us the chance to study an intriguing time around a young, Sun-like star,” said coauthor Stuartt Corder and ALMA Deputy Director in a news release. “We are possibly looking back in time here, back to when the Sun was about 2 percent of its current age.”

The young star, HD 107146, is located roughly 90 light-years from Earth in the direction of the constellation Coma Berenices. Although the star itself is visible in any small telescope, ALMA can probe the star’s radically faint protoplanetary disk. This is the star’s dusty cocoon that coalesces into planets, comets and asteroids.

ALMA’s image revealed an unexpected bump in the number of millimeter-size dust grains far from the host star. This highly concentrated band spans roughly 30 to 150 astronomical units, the equivalent of Neptune’s orbit around the Sun to four times Pluto’s orbit.