2000 December 6
In the famous
Pleiades
star cluster,
a star's light is slowly destroying a
passing cloud of gas and
dust.
The star,
Merope, lies just off the upper right edge of
this recently released picture by the
Hubble Space Telescope.
The cloud, known as
IC 349, and the star have been in existence for millions of years.
In the past 100,000 years, however, part of the
cloud has by chance moved so close to the star -
only 3500 times the Earth-Sun distance -
that the star's light affects the cloud's dust in an
unusual manner.
Pressure of the star's light significantly repels the dust in the
reflection nebula
with smaller
dust particles being repelled more strongly.
Eventually parts of the dust cloud have become
stratified and point toward
Merope,
with the closest particles being the most
massive and so the least affected by the
radiation pressure.
A longer-term result is the
general destruction of the dust by the
energetic starlight.
It is not known whether the cloud will survive this encounter.