Download Forming Planets

Forming Planets
CEA Saclay simulation
New Worlds
How long does it take to make a solar system?
A. 1 million years.
B. 10 million years.
C. 100 million years.
D. 1 billion years.
Gases in Space
• Supernova stars explode and create clouds of gas and dust.
• The gas includes hydrogen, helium, nitrogen, oxygen, etc.
Crab Nebula, 1000 years old
Formation of the Sun
• Stars are formed by a gas/dust cloud contracting due to
gravity.
Orion Nebula, 1 million
years old
Protoplanetary Disk
• Gases begin to swirl around the star.
– Inward from gravity
– Outward from heat
• Angular momentum is conserved.
HR 4796A,
10 million years old
Collisions and Accretion
• From 10 to 100 million years, dust begins to stick together.
• This is called accretion, and is aided by gravity.
– Solid accretion toward star
– Gas accretion outward
Radio image of Epsilon
Eridani,
500 million years old
Migration
• There is more gas and dust near the star for formation.
• A planet moving outward can slow the spin of a star.
– Conservation of angular momentum
Protoplanet 6 MJ,
2 million years old
Keck telescope, 2011
Frost Line
• The heat of a star melts minerals that are close.
• Frozen “ices” dominate at greater distances.
U Hawaii