Explanation:
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In the well known
Pleiades
star cluster, starlight is slowly destroying this wandering cloud of
gas and dust.
The star
Merope lies just off the upper left edge
of this
picture from the
Hubble Space Telescope.
In the past 100,000 years, part of
the cloud
has by chance moved so close to this star -
only 3,500 times the Earth-Sun distance -
that the starlight itself is having a very
dramatic effect.
Pressure of the star's light significantly repels the dust in the
reflection nebula, and
smaller dust particles are repelled more strongly.
As a result, parts of the dust cloud have become
stratified, pointing toward Merope.
The closest particles are the most
massive and the least affected by the
radiation pressure.
A longer-term result will be the
general destruction of the dust by the
energetic
starlight.