What is the star equation?
One can derive the temperature profile in the star by substituting the equation of state for an ideal gas, T = mmH P/rk, where mH is the proton mass and k is the Boltzmann constant, and m is the mean molecular weight, (N.B. this assumes that the only pressure term is due to the gas pressure – i.e. the photon pressure …
How is hydrostatic equilibrium in a star determined by mass?
The more the star is massive a star is, the greater the gravity pressing inward, and the hotter and more dense the star must be inside to balence it’s own gravity. Infer how hydrostatic equilibrium in a star is determined by mass. The star’s density increases, it’s temperature rises, and it’s luminosity increases.
How do you solve a stellar structure equation?
Given the chemical composition of the star, we now have seven equations for the seven unknowns P, M, , L, , T and as functions of r. Hence the equations can be solved….
| r = | radius |
|---|---|
| = | opacity at r |
| a = | radiation density constant |
| c = | speed of light |
How is stellar density calculated?
Mean Stellar Density Mean Density = Mass / Volume.
How do we calculate the area of a star?
A star is well approximated by a SPHERICAL blackbody (surface area = 4 pi R^2), so the formula which gives the total luminosity of a star is the following: Thus, if we know the luminosity L* of a star (found from its intensity and its distance) and if we know the temperature T* of a star, we can compute its radius R*.
What is the relationship between the mass of a star and its rate of formation?
New research from the Harvard-Smithsonian Center for Astrophysics reveals that the correlation between a galaxy’s stellar mass and star formation rate is a tight one. The more stars a typical spiral galaxy contains, the faster it makes new ones.
What is a stellar model?
Stellar structure models describe the internal structure of a star in detail and make predictions about the luminosity, the color and the future evolution of the star. Different classes and ages of stars have different internal structures, reflecting their elemental makeup and energy transport mechanisms.
How do stars vary in mass?
A star’s mass will vary over its lifetime as mass is lost with the stellar wind or ejected via pulsational behavior, or if additional mass is accreted, such as from a companion star.
How much energy does a star output?
This annihilation energy amounts to 1.02 megaelectron volts (MeV), which accords well with Einstein’s equation E = mc2 (where m is the mass of the two particles, c the velocity of light, and E the liberated energy).
What is the power output of a star?
Luminosity, L, is a measure of the total amount of energy radiated by a star or other celestial object per second. This is therefore the power output of a star. A star’s power output across all wavelengths is called its bolometric luminosity.
How do you calculate the perimeter of a star?
The Perimeter will be the sum of ten of the sides of a star point.
What is the relationship between the mass of a star and how long the star will live quizlet?
What is the relationship between the mass of a star and how long the star will live? Higher mass stars live shorter lives.
What is the relationship between a star’s mass and luminosity?
mass-luminosity relation, in astronomy, law stating that the luminosity of a star is proportional to some power of the mass of the star. More massive stars are in general more luminous.
What is the relationship between mass and the lifespan of a star?
A star’s life cycle is determined by its mass. The larger its mass, the shorter its life cycle. A star’s mass is determined by the amount of matter that is available in its nebula, the giant cloud of gas and dust from which it was born.
What is the continuity equation?
The continuity equation is simply a mathematical expression of the principle of conservation of mass. For a control volume with a single inlet and a single outlet, the principle of conservation of mass states that, for steady-state flow, the mass flow rate into the volume must equal the mass flow rate out.
How do you find the total mass of a star?
Integrating the mass continuity equation from the star center ( r = 0 {\\displaystyle r=0} ) to the radius of the star ( r = R {\\displaystyle r=R} ) yields the total mass of the star.
How is the luminosity of a StAR related to its mass?
Considering the energy leaving the spherical shell yields the energy equation: is the luminosity produced in the form of neutrinos (which usually escape the star without interacting with ordinary matter) per unit mass. Outside the core of the star, where nuclear reactions occur, no energy is generated, so the luminosity is constant.
What is the mixing length of a star?
This treats the gas in the star as containing discrete elements which roughly retain the temperature, density, and pressure of their surroundings but move through the star as far as a characteristic length, called the mixing length.