[Mesa-users] Case B mass transfer at solar metallicity

[Debasish Dutta]

Hi Ebraheem,

Thank you very much for your reply. There is a mass transfer, but what I
was worried about is that during the mass transfer phase, we should have
observed a luminosity dip, but here we cannot see any significant
luminosity dip during mass transfer. That was what I meant by a weird HR
diagram.

Regards
Debasish
ᐧ
ᐧ
On Tue, 30 May 2023 at 18:49, Debasish Dutta <debasishdutta1707 at gmail.com>
wrote:

> Hi Ebraheem,
>
> Thank you very much for your reply. There is a mass transfer; but what I
> was worried about is that during the mass transfer phase, we should have
> observed a luminosity dip, but here we cannot see any significant
> luminosity dip during mass transfer. That was what I meant by a weird HR
> diagram.
>
> Regards
> Debasish
> ᐧ
>
> On Mon, 29 May 2023 at 13:07, Ebraheem Farag <ekfarag at asu.edu> wrote:
>
>> Hello Debasish,
>>
>> I'm guessing that by case B mass transfer you mean mass transfer which
>> occurs while the donor is in or evolving toward the Red Giant branch.
>> In that case I believe this is exactly what you are observing. You have a
>> system where M1 (donor) > M2 (BH) when mass transfer begins, as M1 evolves
>> to the RGB, the envelope expands, fills its Roche-lobe and begins stable
>> mass-transfer resulting in an increase in orbital separation until the
>> binary completely detaches ( mass-transfer approaches 0). The donor star
>> (M1) then continues its normal evolution, with wind driven mass-loss
>> stripping the remaining envelope, leaving as a hot exposed helium core at
>> helium depletion (a wolf-rayet star).
>>
>> Hopefully this answers your question.
>>
>> -EbF
>>
>> On Sun, May 28, 2023 at 11:18 AM Debasish Dutta via Mesa-users <
>> mesa-users at lists.mesastar.org> wrote:
>>
>>> Hi,
>>> I am trying to evolve a binary system with a black hole companion. I am
>>> interested in getting a Case B mass transfer. For lower metallicity models
>>> (SMC, LMC and Zsun/10), it seems to work well. However, for higher
>>> metallicity (~solar) massive models, I could not get the Case B mass
>>> transfer. I was using the initial orbital periods as 70 days for the lower
>>> metallicity models. In the case of solar metallicity, if I use an extended
>>> period (~450 days), I get some weird HR diagrams with the mass transfer
>>> phase almost non-existent. I  have attached my inlists and also a HR
>>> diagram of a 42 solar mass model at solar metallicity (mass ratio=0.6).
>>>
>>> I would be glad if someone could help me regarding this.
>>>
>>> Regards
>>> Debasish
>>> ᐧ
>>> _______________________________________________
>>> mesa-users at lists.mesastar.org
>>>
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>>>
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