.. _5M_cepheid_blue_loop:

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5M_cepheid_blue_loop
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.. tags:: star, cepheid, blue-loop, instability-strip, core-helium-burning, intermediate-mass

This test case checks that the evolution of a 5 |Msun|, metal-poor Z=0.008, helium-enriched Y=0.256 model
executes a blue-loop in the HR diagram and crosses the classical Cepheid instability strip boundaries three times.

This test case has two parts. Click to see a larger view of a plot.

* Part 1 (``inlist_start``) creates a pre-main sequence model and evolves it to the onset of core helium burning, just past the tip of the Red Giant branch.

* Part 2 (``inlist_cepheid_blue_loop``) continues the evolution as core helium burning proceeds. The model executes a blue loop, with the red edge and blue edge of the classical Cepheid instability strip boundaries shown in the HR diagram:

.. image:: ../../../star/test_suite/5M_cepheid_blue_loop/docs/hr002086.svg
   :width: 100%

pgstar commands used:

.. code-block:: console

 &pgstar

   file_white_on_black_flag = .true. ! white_on_black flags -- true means white foreground color on black background
   file_device = 'png'            ! png

   !file_device = 'vcps'          ! postscript

    pgstar_interval = 10

   HR_win_flag = .true.
   HR_win_width = 12
   HR_win_aspect_ratio = 1.2 ! aspect_ratio = height/width

   HR_logT_min = 3.6
   HR_logT_max = 4.3
   HR_logL_min = 2.0
   HR_logL_max = 3.4

   ! file output
   HR_file_flag = .true.
   HR_file_dir = 'pgstar_out'
   HR_file_prefix = 'hr'
   HR_file_interval = 100 ! output when mod(model_number,HR_file_interval)==0
   HR_file_width = 15 ! negative means use same value as for window
   HR_file_aspect_ratio = -1 ! negative means use same value as for window

 / ! end of pgstar namelist


Last-Updated: 29May2021 (MESA e37f76f) by fxt