Planet Building in HD 100546
More than 100 billion boulders may be swarming
in the disk around nearby star HD 100546.
In a scene thought similar to the
early years of our own
Solar System, ever larger rocks are growing by
colliding and accreting dust as the messy business of
planet formation appears to be underway.
For an Earth-like planet in such a hostile environment,
the sky would be lit continuously with
streaking meteors
and the ground would rumble continuously with
impacts.
Pictured above, the swirling disk of
dust, gas, and
rocks of HD 100546 is visible as the dark region
surrounding the image center.
The bright light and six-pointed
diffraction spikes from the
central star have been removed from the
false-color image.
HD 100546 is visible with binoculars towards the southern
constellation of
Musca, and is a relatively nearby 335 light-years away.
Similar planet-building systems, dubbed
proplyds, have
recently been found in
Orion, where many emerging
planets there must survive the boiling
radiations of
neighboring bright stars.