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The Birth of Solar Systems
Formation of a protostar and disk
Collapse of and interstellar cloud
The disk condenses and dissipates
A solar system
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The Birthplace of Stars
The space between the stars is not completely
empty. Thin clouds of hydrogen and helium, seeded
with the dust from dying stars, form in
interstellar space.
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Hot Stars make their Nurseries glow
Optical
The Orion Region Infrared
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Dark Clouds gather
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Molecular Clouds
Sometimes (especially in spiral arms), the gas is
compressed enough that the dust is thick and
gravity can collapse knots in these molecular
clouds to make new stars.
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Where Stars Begin
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A little bit of spin goes a long way
Galactic shear and turbulence give every core a
little spin (once round in 10 million years). But
they get a lot smaller, and the spin goes up to
orbital!
It is for this reason that we believe there are
many planetary systems it is part and parcel of
the star formation process to make a disk.
Typical Galactic spin makes disks about the size
of our Solar System
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The Sword of Orion
The nearest great stellar nursery to us is the
great Orion molecular cloud which is about 1000
light years away, and manufacturing thousands of
stars. This is probably how the typical star is
made.
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The glowing tip of a molecular cigar
The Orion nebula is powered by 4 high mass
luminous stars, which have cleared out their
birthplace and are eating at a long cloud pointed
at us.
The Trapezium
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Near them, lower mass stars are forming
Hubble Space Telescope
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They look like little windsocks
The blast from the luminous stars is eating away
at the little guys
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The heart of them contains a potential new solar
system
Proplyds are new star-disk systems
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Orion Proplyds
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A whole cluster of new stars is born before us
Hundreds of young stars, often with disks, have
been seen.
Disks in Orion
Orion in the near infrared
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The Star-Disk System Forms
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And emits powerful bipolar jets
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which extend for many light years
negative image
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The jet shocks are called Herbig-Haro Objects
Orion A
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The jet is powered by the stellar magnetic field
and rotation, and takes away excess angular
momentum
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piercing back out into the cloud
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T Tauri Stars
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The Young Star is Very Active
The magnetic flux is hundreds of times stronger
than the Sun, and huge starspots are seen. The
star itself is 3 times bigger.
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The stage is set for planet formation
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We see remnant disks around other stars
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Star Formation is Beautiful, but ephemeral
Within about 10 million years, the birth-cloud is
shredded, and the disks are dissipated. The
process of starbirth has ended.