The Galaxy Flashcards
1
Q
What is the equation for hydrostatic equilibrium?
A
dP/dr = -GM(r)/(r^2) x p(r)
2
Q
What are the equations and relationships for star lifetime on the main sequence?
A
- t = fuel/ energy
- t = Etotal/L
- t proportional to m/L
- Tms = Tsolar x (m/msolar)^-2.5
3
Q
What are the equations that relate to dust shielding?
A
- Av = 3.2E(B-V)
- m - M = 5logd -5 +Av
4
Q
What are the equations for P Cygni lines?
A
Wind velocity = difference in wavelength/ peak wavelength x c
5
Q
What is the equation for mass loss?
A
dM/dt = 4pi r^2 p(r)v(r)
where p(r) = density and v(r) = velocity
6
Q
What is the equation for number density?
A
N = No e^ -|z|/H
