[Mesa-users] Stars older than universe

[Rob Farmer]

Hi,
What's the lifetime of a 0.489msun star? I don't know but it's longer than
the age of the Universe, so it does not surprise me that it will keep
evolving until then.

You are starting with a 0.489msun star, I assume you choose that as the
current mass of 2MASSJ165002074 is expected to be that?  If so, have you
considered that your star might have had a higher initial mass and then
lost mass to its companion in the binary? So if you started with a higher
initial mass star then it would evolve faster.

I would suggest trying to evolve both stars in a binary from the beginning
and try running many different initial masses to find one that ends up with
the correct mass for 2MASSJ165002074.

Rob



On Mon, 14 Dec 2020 at 08:49, Gökhan Yücel <gokhanyucel at akdeniz.edu.tr>
wrote:

> Hello everyone,
>
> I have been doing evolution of binary stars that their stellar parameters
> are well known until mass transfer starts. To do that, I simple evolve
> single stars until they reach to their current radii and save their models.
> After that I use binary mode to evolve them. I have been successful to do
> that for a while but I have encountered some sort of situations while doing
> a single star evolution. Some very low mass stars, M spectral type
> specifically, has an age more than universe itself according to models. I
> believe something is wrong in here. I have checked the parameters and how
> they had been calculated and there is nothing in this area. This has
> happened some other stars, all of them are very late types, too.
>
> M = 0.489 Msun, R = 0.453 Rsun
>
> I attached the files. I am using mesa version of "r12115" and SDK version
> of "20190830".
>
> What am I doing wrong?
>
> Sincerely,
> Gökhan
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.mesastar.org/pipermail/mesa-users/attachments/20201214/12c2c9b1/attachment.htm>