Re: Yahoo! News Story - Planet Formation is Child's Play - Yahoo! News
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> Planet Formation is Child's Play - Yahoo! News
south of Epsilon and west of Delta-3 Tauri around the Hyades
9 Gemini 29
Lick Ca Survey (LkCa) 15 (Tauri)
near Tau Tauri
12 Gemini 13
Story reposted below.
Mark A. Holmes
Planet Formation is Child's Play
SPACE.com Thu Nov 29, 5:00 PM ET
Astronomers think they have found the two youngest solar systems ever
detected, where infant planets could be sweeping up dust and creating
voids in protoplanetary disks 450 light-years from Earth.
NASA's Spitzer Space Telescope observed the ring-like gaps, which
could signal the earliest signs of rocky planet formation around two
young stars located in the constellation TaurusUX Tau A and LkCa 15.
Both stars are about 1 million years old, which is 10 times younger
than other known planet-forming systems.
"Previously, astronomers were seeing holes at the centers of
protoplanetary disks," said Catherine Espaillat, an astronomer at the
University of Michigan in Ann Arbor. Such holes are typically thought
to be caused by photoevaporation, or stars burning dust away into
But instead of central holes, Espaillat's team saw ring-like gaps in
the spinning planetary materials.
"It's more like a lane has been cleared within the disk. The existence
of planets is the most probable theory that can explain this
structure," she said, as the lanes are likely too distant from the
star to photoevaporate.
The idea is similar to touching a dusty record as it rotates, clearing
a ring in the mat of particles; planets, however, use their growing
gravity to sweep up the dust.
The Dec. 1 issue of Astrophysical Journal Letters will detail
Espaillat and her colleagues' findings about the infant solar systems,
which they said could help explain our own planet's past.
"We are looking for our history," said University of Michigan
astronomer Nuria Calvet, who worked with Espaillat on the research.
"We are looking for the history of solar systems, trying to understand
how they form."