# 5M_cepheid_blue_loop¶

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:

pgstar commands used:

&pgstar

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

!file_device = 'vcps'          ! postscript
!file_extension = 'ps'

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