[Mesa-users] Errors on bolometric corrections

[Marc Pinsonneault]

If you want to check the impact of different assumed BC values, they are
independent of the evolution calculation (e.g. you can do a table look-up
in any atmospheres model for colors, BCs and so on in a post-processing
step). So you could try different atmospheres models to measure theoretical
systematics (see Zinn et al. 2019 for an example of this, with some cases
to try). Neglecting systematic errors in BC corrections, the values on an
isochrone are exact; the issue is in how you use the isochrones relative to
real stars. If you have a typical measurement error for an application to
stars, e.g. a stellar Teff is only known to 50 K, then there is an
effective error associated with sampling the isochrones at +/- 50 K. The
same applies if you think that there can be a systematic error in the true
isochrone locus, e.g. at a given L, Teff pair there is a different mass and
surface gravity.  We argued in Zinn+ 2019 that the systematics between
methods become important at the couple of percent level.

cheers

Marc Pinsonneault

On Tue, Aug 9, 2022 at 4:00 PM Aaron Dotter via Mesa-users <
mesa-users at lists.mesastar.org> wrote:

> Hi Jeremy
>
> Worthey & Lee is an empirical calibration.  What MESA provides is not, as
> Rob points out, so does not come with uncertainties attached.  They are
> what they are.
>
> Aaron
>
>
> On Tue, Aug 9, 2022 at 15:52 Jeremy Sakstein <sakstein at hawaii.edu> wrote:
>
>> HI Aaron,
>>
>> I think it depends on whether the BCs are calibrated empirically e.g.
>> using isochrone fitting or theoretically using atmosphere models but I
>> would expect some uncertainty e.g. the Worthy and Lee code includes errors
>> due to the former.
>>
>> Cheers,
>>
>> Jeremy
>>
>> On Tue, Aug 9, 2022 at 9:50 AM Aaron Dotter <aaron.dotter at gmail.com>
>> wrote:
>>
>>> Hi Jeremy,
>>>
>>> What is responsible for these errors?
>>>
>>> Aaron
>>>
>>>
>>> On Tue, Aug 9, 2022 at 15:40 Jeremy Sakstein <sakstein at hawaii.edu>
>>> wrote:
>>>
>>>> Hi everyone,
>>>>
>>>> I'm interested in using MESA to study main-sequence stars and I'd like
>>>> to output bolometric corrections with error bars.
>>>>
>>>> I checked through the colors module (I'm using version 12778) and as
>>>> far as I can tell there is no way to output errors. I also checked the
>>>> paper the BCs are taken from and they don't report errors.
>>>>
>>>> Is there any way to get MESA to estimate the errors on the bolometric
>>>> corrections?
>>>>
>>>> If not, can someone recommend some other BC code/tables that I can use
>>>> to produce BCs with errors using MESA output?
>>>>
>>>> Cheers,
>>>>
>>>> Jeremy
>>>>
>>>>
>>>> --
>>>> Jeremy Sakstein (He/Him/His)
>>>> Assistant Professor of Theoretical Physics
>>>> Department of Physics & Astronomy
>>>> University of Hawaiʻi at Mānoa
>>>> Watanabe Hall
>>>> 2505 Correa Road
>>>> <https://www.google.com/maps/search/2505+Correa+Road+Honolulu,+HI,+96822,+USA?entry=gmail&source=g>
>>>> Honolulu, HI, 96822, USA
>>>> <https://www.google.com/maps/search/2505+Correa+Road+Honolulu,+HI,+96822,+USA?entry=gmail&source=g>
>>>> http://www.jeremysakstein.com
>>>> _______________________________________________
>>>> mesa-users at lists.mesastar.org
>>>> https://lists.mesastar.org/mailman/listinfo/mesa-users
>>>>
>>>>
>>
>> --
>> Jeremy Sakstein (He/Him/His)
>> Assistant Professor of Theoretical Physics
>> Department of Physics & Astronomy
>> University of Hawaiʻi at Mānoa
>> Watanabe Hall
>> 2505 Correa Road
>> <https://www.google.com/maps/search/2505+Correa+Road+Honolulu,+HI,+96822,+USA?entry=gmail&source=g>
>> Honolulu, HI, 96822, USA
>> <https://www.google.com/maps/search/2505+Correa+Road+Honolulu,+HI,+96822,+USA?entry=gmail&source=g>
>> http://www.jeremysakstein.com
>>
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