Class Notes (1,100,000)
CA (650,000)
UTSC (30,000)
Astronomy (100)
Lecture

ASTA02H3 Lecture Notes - Thermostat, Brown Dwarf, Ideal Gas


Department
Astronomy
Course Code
ASTA02H3
Professor
Parandis Khavari

Page:
of 7
Astronomy - Session 7
H-R Diagram
luminosity and absolute magnitude
formulas
inversely proportional
ex.
and
Interstellar Matter (ISM)
combination of gas and dust
not uniform
temperature
not uniform
warmest temperature, 30 K
colder
more dense
nebula
clumped areas of ISM

low temperature
allows atoms to bind
giant molecular clouds
mostly Hydrogen
accompanied by CO2
CO2 emission
trace where denser clouds/clumps
more matter
gravity
gravitational collapse
must have be triggered by a mechanism
this mechanism usually comes in form of a shock wave
shock wave
a sudden change in pressure that travels as an intense sound wave
triggered by
1. birth of a hot star
2. supernova explosion
3. collision of two ISM clouds

mass of GMC (giant molecular cloud)



spiral galaxy
arms push and compress gas
(similar to food processor)
Q. What factors oppose collapse (gravitational)?
low temperature 
molecular cloud
no nuclear fusion
movement of particles
thermal energy opposes gravity
atoms move at 
average velocity


Boltzmann constant

mass of particle
factors opposing gravitational collapse
1. thermal energy of particles
2. magnetic field
3. motion of turbulent gas
luminosity
(area)

  
enemy of gravity
motion
turbulent gas
thermal energy
star formation
thousands at the same time
approx. six million years

star cluster
a group of stars that are formed together
gravitationally bound
stellar association
hot and gravitationally bound
open cluster
weak and gravitationally bound
reflection nebula
know the different types of nebula
evidence of the formation of protostars
protostars
infrared
peak of temperature: infrared
not visible because