Star

Stellar evolution based on the code by Peter Eggleton (MNRAS, 1971, ...) with additional parameters for making pseudo-stars in which various physical constants have different values.

The problem of computing stellar evolution and examining the models produced has been broken down into a set of components each of which encapsulates a distinct task, such as storing the internal state of a star, or a way if displaying it, or a whole sequence of models.

Most objects live in list, and each list holds only one type of object. When an object needs to refer to an object of a different type, it normally gets a reference to the list which contains possible target objects and the user can pick the one to be used. This means that you can have multiple instances of almost any object.

The objects specific to stars are:

    StarDataTables
    StarModel
    StarView
    StarModelSequence
    HRDiagram
    StarCtrl
    PseudoPhysFactors

There are two user interface components with those - StarViewEditor and HRDiagramEditor. A number of standard components can also be used in conjunction with these, including color tables, compound applets and recorded demonstrations.

Each component has documentation explaining its own variables and mode of operation (click the "?" button in the top right when viewing a component).

On startup, various components are loaded automatically for stellar evolution - opacity tables for 2% metallicity, and a one solar mass initial model (to avoid this, see the star tutorial.

To get started quickly, use the following steps to create an evolutionary sequence:

1. Start the stellar evolution version of Catacomb as usual Various windows will appear, including a display of this page.

2. In the StarModeSequence window, click "initialize" It may take a few seconds, reading the data tables, but will then say "initialized successfully" in the message area near the bottom.

3. Click "run" to start the calculation running. The step number is displayed in the message area.

4. In the HRDiagram menu, select "edit" . This will open a window to display the current HRDiagram.
5. In the window labelled "HRDiagram", click the mouse on the graph and then press "f" on the keyboard . This is one of the many ways to change the ranges of the graphs so as to examine the data. Some of the others include left clicking to zoom in, right-clicking to zoom out, press and drag to pan, clicking to the left or below the axes to change just one axis, using the menu at the top right, or typing "h" and using the resulting window to set things by hand.
6. Click with the right mouse button near the middle a couple of times to center the data.

7. Click a point in the HRDiagram window to display properties of the corresponding model.

8. Select "edit" under the starView menu . A new window will open for showing the internal structure of the latest model, or of any model you click on in the HR diagram. Complete structures are only available for models marked with fat dots. The X and Y menus select what is plotted against what.

There are many more facilities available - browse the documentation listed above or just try things out.