10. Stellar Nurseries

Joshua Barnes -- Fall 1999

Stars are born inside great clouds of cool gas and dust. Such a cloud may contain thousands of denser lumps of gas; some of these lumps collapse under their own weight. This gravitational compression heats the gas until thermonuclear reactions can occur. When the production of nuclear energy matches the rate at which energy escapes into space, the collapse halts and a main-sequence star is born.

Topics:

• Molecular clouds
• Gravitational contraction
• Protostars
• Main-sequence stars
• Star clusters

Web Resources:

• Star-formation in Neighbor Galaxy [source]

  A very large star-formation region in a neighboring spiral galaxy.

• Orion and its Nebula (0.6 Mbyte mpg) [source]

  Animation showing a nearby star-formation region in the constellation of Orion.

• The Orion Nebula [source]

  Close-up of the star-formation region in Orion.

• Columns of Gas in Eagle Nebula [source]

  Dense clouds of gas `boiling off' due to radiation from massive stars.

• When I Heard the Learned Astronomer

  Faint praise for astronomy lectures...

• Toilet Anatomy [source]

  From a website on running toilets and how to fix them.

Homework 10: Main-Sequence Stars, due 11/01.

Quiz 10: How Hot The Sun?