Your First Kaitiaki Run

The simplest example of Kaitiaki is to run the evolution of a \(1 M_\odot\), solar metallicity star. This can be done with the following snippet:

import kaitiaki

STARS = kaitiaki.STARS.STARSController()
STARS.blit()
STARS.load_default_modin()
STARS.run()

Let’s examine these in more detail.

How STARS works

STARS requires fundamentally three customisable things:

  1. A model input

  2. A data file

  3. Opacity tables.

modin

The model input – often shortened to the modin file – is the state of the model upon start of simulation. Kaitiaki ships a sample model input – for \(1~M_\odot,~Z=0.020\) (if you want to do something more interesting than the sun, you need to inflate it yourself – see a future tutorial). The STARS.load_default_modin() creates that file on disk for you.

data

The data file is a list of potential inputs. The STARS manual has a more detailed list of parameters, but the default ones are set up to allow you to just immediately evolve a \(1~M_\odot\) model until roughly the AGB phase. This is loaded in STARS.blit().

COtables

The opacity tables are what enable you to run different metallicities. For instance, if you wanted to run a \(Z=0.014\) model, you would need to load the z014 COtable. This is loaded in STARS.blit().