mesa-users] Manual Change of Accretion Composition

[Max K. <ka...@rp...>]

Hello,

In an attempt to create my own nova, I used the model 1.000_Tc_3e7.mod in
mesa/data/star_data/white_dwarf_models. This is a pure C/O white dwarf of 1
solar mass. The goal is to get it to go nova, so I set an accretion rate of
5 x 10^-9 (units are solar masses per year). However, the default behavior
for accretion is to use the same composition for the accreted matter as
there is on the surface. Since adding C and O to the surface wouldn't yield
the nova I was looking for, I set the following in the controls namelist:

mass_change = 5d-9
accrete_same_as_surface = .false.
accretion_h1 = 0.75
accretion_h2 = 0.
accretion_he3 = 0.
accretion_he4 = 0.25

However, when I try to run with these settings on, the run cites
"adjust_mass_failed", and crashes after hitting the default max number of
backups (15). I tried the same settings on a different case and got the same
error. If anyone has experience with changing the accretion composition, I
would appreciate it if you could give some insight as to what I might be
doing wrong. Thanks.

Max Katz
Rensselaer Polytechnic Institute
Physics, Class of 2011