[Mesa-users] Eccentric binary evolution

[Shunyi Lan]

Dear Ruggero, 

Thanks for the reply!

Best regards,

Shunyi



-----原始邮件-----
发件人:"Ruggero Valli" <ruvalli at MPA-Garching.MPG.DE>
发送时间:2023-09-18 17:45:47 (星期一)
收件人: mesa-users at lists.mesastar.org
抄送:
主题: Re: [Mesa-users] Eccentric binary evolution



Dear Shunyi,

To my knowledge, the binary (initial) separation refers to the semimajor axis of the system. As a consequence, it would be expected not to see a change of this quantity even for timescales smaller than the orbit.
But actually, MESA doesn't keep track of the orbital phase, the implicit assumption is that timescales practical for stellar evolution will be much larger than the orbital period.
For phase dependent processes, the orbit is divided into a number of steps (see anomaly_steps in binary_controls) and integrated through a full orbit to obtain the secular changes.

Best regards,
Ruggero

On 9/18/23 10:38, Shunyi Lan wrote:


Dear MESA users and developers:




I hope this email finds you well. I have some questions regarding eccentric binary models in MESA that I would greatly appreciate your insights on.

Firstly, I would like to understand the definition of the initial separation under an eccentric scenario. Is it defined in terms of the semi-major axis, minor axis, or is there another criterion for this?




Secondly, despite setting the timestep below the orbital timescale, I have been unable to observe binary separation oscillations. I'm puzzled by this and would like to seek any guidance on what might be causing this issue.

Best regards,

Shunyi Lan



_______________________________________________ mesa-users at lists.mesastar.orghttps://lists.mesastar.org/mailman/listinfo/mesa-users
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.mesastar.org/pipermail/mesa-users/attachments/20230919/1615dff1/attachment.htm>