NATS 1740 Lecture Notes - Lecture 10: Brown Dwarf, Triple-Alpha Process, Main Sequence

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Michael De Robertis, Alireza Rafiee

Document Summary

Fusion create thermal temperature (+) brown dwarfs. A brown dwarf is hot, emits infrared light because of the internal heat left over from the contraction. Its luminosity gradually declines with time as it loses thermal energy. Infrared observation can reveal the brown dwarfs because they are still relatively warm and luminous. Stars more massive than 300m. sun would blow apart. Stars less massive than 0. 08m. sun can"t sustain fusion. Stars are born in cloud, relatively dense molecular clouds => collapsed under gravity => protostar surrounded by a spinning disk of gas (=> may also fire jets of matter outward along its poles) Stars are > 300m. sun would be so luminous that radiation pressure would blow them apart. How does it die: what are the life stages of a low-mass star? (1) when a star mass is small (1) when a star bigger than a solar mass.