Astronomy 1021 Lecture : Star Formation

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Chris Racknor

Document Summary

Stars form from the gravitational collapse of an interstellar cloud. Stars start shining when temperature is high enough for nuclear fusion. Many pictures we have of stars are photo shopped. The youngest star clusters are all surrounded by large amounts of dust and gas (the interstellar medium [ism]) It seems that large interstellar clouds somehow become stellar nurseries. The space between the stars seems largely empty at visible wavelengths. There is a fair amount of material between the stars and this is called the interstellar medium. Most of the interstellar medium is in the form of low density gas (mostly hydrogen and helium) in clouds called nebulae. These clouds do contain a small (about 1%) amount of heavier elements mostly in small solid grains referred to as dist. The interstellar medium has and overall composition very similar to the sun s.