Digital Demo Room
Stellar Structure and Evolution Simulator
Advanced Level Interface
Only the mass, metallicity, and times of star formation fields can take more than one value.
For multiple values input into these fields, separate by commas and/or spaces.
Mass of Stars
Masses are in solar units and must have values between 0.1 and 120 solar masses. You must enter a value or values for the mass to run the simulation unless you enter a value into the randomly chosen mass field below.
Metallicity of Stars
Metallicity is the fraction of a star's composition that is made up of elements heavier than Helium. Metallicities must have values between 0.0001 and 0.03. If no values are input, metallicities will be set to solar metallicity. Only masses input above can be assigned metallicity in this way.
Number of additional randomly massed stars
The number of randomly massed stars must be less than 1000. The distribution of the random masses is determined by a stellar inital mass function. Values for the lowest and highest generated masses may be input by the user. However, the lower mass limit and upper mass limit must be no lower than 0.1 solar masses and no higher than 120 solar masses respectively. If no values are input, the default values displayed will be used. Note that stars with masses less than 0.9 solar masses do not evolve on a practical time scale. Metallicities are assigned randomly.
Lower Mass Limit:
Upper Mass Limit:
Stars spend most of their lives on the main sequence before evolving, setting beginning time later can skip through this relatively uneventful period. Normally movies start at time zero.
Times are in millions of years (MYear), and must have values between 5 and 30000 MYear. It is recommended that the value be between 20 and 150 MYear for high mass stars and between 150 and 15000 MYear for low mass stars.
Number of Frames
The movie is created in about 30 seconds for every 500 frames, but more frames better show the evolution of the stars.
Type of Star Formation
Initial Burst creates all the stars you inputted at the beginning. Star Bursts creates stars divided up between the beginning and the times you enter below. Continous star formation creates new stars throughout the simulation. Increasing or decreasing continous increases or decreases the rate of birth over time.
Constant Continous Formation
Increasing Continous Formation
Decreasing Continous Formation
Times of Star Formation
The times are in millions of years (MYear). Stars often form in bursts, there will be an initial burst, but additional bursts can be used to simulate more complicated galaxies.
If the checkbox is checked, the simulation will create evolutionary tracks on the HR diagram for each star as the star evolves. If it is not checked, the simulation will just evolve the star without creating its tracks on the HR diagram.
Evolution Tracks On