[Mesa-users] Science Fair

Tue Feb 2 17:44:40 UTC 2021

Hello

My science fair is on February 17th. Currently, my data consists of 8 stars
with the initial metallicities of: 0.02, 0.004, 0.001, 0.0003, 0.0001,
0.01, 0.03, 0.04. I stop the evolution of the star at the end of the
asymptotic giant branch. The following links are all the papers I have read
but I am missing a few recent ones:
https://ui.adsabs.harvard.edu/abs/2014MNRAS.445.2340W/abstract
https://arxiv.org/pdf/1303.2207.pdf
https://iopscience.iop.org/article/10.1086/312213/pdf
https://www.aanda.org/articles/aa/pdf/2014/12/aa23924-14.pdf
https://iopscience.iop.org/article/10.1086/300499/pdf
https://iopscience.iop.org/article/10.1086/306887/pdf
https://iopscience.iop.org/article/10.1086/305327/pdf
https://inspirehep.net/literature/490342
https://www.aanda.org/articles/aa/pdf/2004/22/aagc172.pdf

Most of my research was focus on the type 1a supernovae but then I pivoted
to focusing on the Red and Asymptotic Giant Branch. Currently, I am in the
process of reading stellar interiors - physical principles, structure, and
evolution second (2nd) edition. I understand to an above basic degree how
metallicity influences stellar evolution but I am unsure of how it
influences the interaction of photons and metals. I am not familiar with
the photon-metal interactions.

I have created HR diagrams for all my models and the following link is for
a google drive with all of the diagrams.

https://drive.google.com/drive/folders/1fJ1q1P0HE-iWWgzy7OPp1g7UJTb8Cqv9?usp=sharing
 Each of the graphs represents one model. All have an initial mass of 2.0
solar masses. The only difference in the input parameters for the stars is
the metallicity which is indicated in the graph title. The final.png graph
is all of the models combined in one graph. The following is the respective
colour for each initial metalicity.
Initial metallicity: 0.02  Color: black
Initial metallicity: 0.004  Color: blue
Initial metallicity: 0.001  Color: red
Initial metallicity: 0.0003  Color: yellow
Initial metallicity: 0.0001  Color: green
Initial metallicity: 0.01  Color: purple
Initial metallicity: 0.03  Color: pink
Initial metallicity: 0.04  Color: orange

Thank you for the idea to look at different variations of the sun but I am
unsure if I have enough time to collect the data for that experiment. I am
intrigued by photon and metal interactions and I am wondering how could I
use the data I already have to display a relationship between the photon
and metal interactions and metallicity. I was also considering looking into
nucleosynthesis as a means to show a nuclear physics concept but I am
unsure of what concept I could look into, considering my data. Also, if you
have any recommendations for research papers or ideas that could
potentially inspire me or explain a concept to me that would be incredibly
appreciated.

Thank You
Karan Jain

On Tue, Feb 2, 2021 at 11:49 AM Jacqueline Goldstein <
jacqueline.goldstein at gmail.com> wrote:

> Karan,
>
> That’s an amazing amount of initiative. Way to go.
> When is your science fair?
> What is the data that you’ve already collected?
> What books and papers have you read?
>
> I’m going to guess that very few people know, as you do already, that
> stars a born with different masses and metallicities.
> When you say that you don’t know how to relate metallicity to a physical
> concept, do you mean that you don’t know how metallicity influences stellar
> evolution? Assuming a fixed initial hydrogen abundance (X) and helium
> abundance (Y), the metalicity (Z) [such that X + Y + Z  = 1] can influence
> the surface properties of a star by influencing how photons interact with
> metals. Are you familiar with this?
>
> Since you’ve already evolved a 2 Msun star with various metallicities
> (which metallicities did you use?), you could compare the various surface
> properties of your stellar models as they evolve, or at one point in time.
> Are you familiar with the Hertzsprung-Russell Diagram?
>
> Alternatively, if you’re looking for a narrative that others may be more
> familiar with, you could simulate a 1 solar mass star (like our Sun) and
> compare its surface properties (luminosity, temperature, radius) to what it
> would be with various metallicities (fewer metals, meaning it formed from
> less evolved gas; or more metals, meaning it formed from more evolved gas).
> The types of planets that stars of varying metallicities would produce
> varies too; but you could play out a hypothetical - what would our Sun look
> like to people on Earth at various metalicities?
>
> I am including mesa-users in the reply so that others can have input.
>
> Sincerely,
>
> Jacqueline Goldstein, Ph.D. (she/her/hers)
> Astronomy | Life Sciences Communication
> University of Wisconsin — Madison
> http://www.astro.wisc.edu/~jgoldstein
>
>
>
> On Feb 1, 2021, at 8:43 PM, Karan Jain <karanjain2004 at gmail.com> wrote:
>
> Hello, my background in physics is just high school classes and some
> self-study outside of class by reading a few textbooks. As for astronomy, I
> am relatively new to it but I have spent the last 4 months reading up on
> research papers relating to my project and reading astronomy textbooks. I
> got the idea to look at the effects of metallicity after I learned of MESA
> and I read some papers. I was looking for a science fair project to do and
> my strongest subject was computer science but I also wanted to learn more
> about astronomy so I looked for software that would allow me to simulate
> the evolution of a star and would provide data on the star and MESA was the
> perfect fit. My idea for examining the effects of a variable metallicity
> was inspired by a research paper I read that examined the effects of a
> changing metallicity on the type 1a supernovae of a white dwarf. I also
> have a strong chemistry background so I understood metallicity the best out
> of all the parameters MESA provides. It is a high school level science fair
> that runs in the entire Pennsylvania state. I am a junior in high school
> currently and the science fair that I am competing in had a physics
> category instead of an astronomy or astrophysics category so I signed up
> for the physics category. I have neither an advisor nor a mentor for this
> project. I am hoping to use the data I collected to show a physics or
> astrophysics concept. For example, a project that was done last year
> proved, the already proven idea, that the universe was expanding by looking
> at the velocities of stars.
>
> Thank You
> Karan Jain
>
>
>
> On Mon, Feb 1, 2021 at 9:21 PM Jacqueline Goldstein <
> jacqueline.goldstein at gmail.com> wrote:
>
>> Hi karan,
>>
>> If I can ask some questions…
>>
>> What is your background knowledge of physics and astronomy?
>> How did you get the idea that you’re developing now?
>> What level is this science fair for?
>> Are you working with an advisor or mentor?
>>
>> Sincerely,
>>
>> Jacqueline Goldstein, Ph.D. (she/her/hers)
>> Astronomy | Life Sciences Communication
>> University of Wisconsin — Madison
>> http://www.astro.wisc.edu/~jgoldstein
>> <https://www.google.com/url?q=http://www.astro.wisc.edu/~jgoldstein&source=gmail-imap&ust=1612838612000000&usg=AOvVaw2n2PXDsiAagPaz8MFWNEzY>
>>
>>
>>
>> On Feb 1, 2021, at 11:56 AM, Meisel, Zach via Mesa-users <
>> mesa-users at lists.mesastar.org> wrote:
>>
>> Hi Karan,
>>
>> It may help to consider this paper:
>> https://doi.org/10.1046/j.1365-8711.2000.03426.x
>> <https://www.google.com/url?q=https://www.google.com/url?q%3Dhttps://doi.org/10.1046/j.1365-8711.2000.03426.x%26source%3Dgmail-imap%26ust%3D1612807079000000%26usg%3DAOvVaw0_0L96edj-1yp-L_8aglwV&source=gmail-imap&ust=1612838612000000&usg=AOvVaw1h8UT-4rX82LXBIEXTEUQW>.
>> Hurley, Pols, & Tout MNRAS 2000 looked at how metallicity impacts stellar
>> evolution. It’s a bit intense for a science fair project, but may give you
>> some ideas. For instance, Figure 20 shows how the mass of the remnant at
>> the end stellar evolution is different for two different initial
>> metallicities; Figure 3 compares stellar evolution tracks on the HR
>> diagram; and Figure 4 essentially compares the rate at which core fuel is
>> burnt.
>>
>> The reasons for the various impacts can get a little complicated, so
>> you’re going to want to cozy up with a stellar evolution textbook. Stan
>> Woosley’s online notes discuss the impact of metallicity on stellar
>> evolution on slide 12 of this lecture:
>> http://www.ucolick.org/~woosley/ay220-15/lectures/lecture7.4x.pdf
>> <https://www.google.com/url?q=https://www.google.com/url?q%3Dhttp://www.ucolick.org/~woosley/ay220-15/lectures/lecture7.4x.pdf%26source%3Dgmail-imap%26ust%3D1612807079000000%26usg%3DAOvVaw0HBuS7T5bM5fHAd7sCVPBm&source=gmail-imap&ust=1612838612000000&usg=AOvVaw2jB2KwakG7klEVAvnHNqfl>.
>> Some good free books to consult are Ed Brown’s “To Build a Star”
>> https://web.pa.msu.edu/people/ebrown/docs/intro-stellar-physics.pdf
>> <https://www.google.com/url?q=https://www.google.com/url?q%3Dhttps://web.pa.msu.edu/people/ebrown/docs/intro-stellar-physics.pdf%26source%3Dgmail-imap%26ust%3D1612807079000000%26usg%3DAOvVaw3uVvxGP4KaSfyno64z9-Qz&source=gmail-imap&ust=1612838612000000&usg=AOvVaw21hn-YcziibXesFPMakHMh>
>>  and Onno Pols’s “Stellar Structure and Evolution”
>> http://www.ucolick.org/~woosley/ay112-14/texts/pols11.pdf
>> <https://www.google.com/url?q=https://www.google.com/url?q%3Dhttp://www.ucolick.org/~woosley/ay112-14/texts/pols11.pdf%26source%3Dgmail-imap%26ust%3D1612807079000000%26usg%3DAOvVaw0lEjgknJTkRIJiN0vrCEsB&source=gmail-imap&ust=1612838612000000&usg=AOvVaw19NxvtbYqOC7HD2PZfZNSP>.
>> These are aimed at the advanced undergraduate or beginning graduate level.
>>
>> -Zach
>>
>> ----
>> Zach Meisel
>> Associate Professor of Physics & Astronomy
>> Director, Edwards Accelerator Laboratory
>> Ohio University
>> Email: meisel at ohio.edu
>> Web: http://inpp.ohio.edu/~meisel
>> <https://www.google.com/url?q=http://inpp.ohio.edu/~meisel&source=gmail-imap&ust=1612838612000000&usg=AOvVaw0u7N5TAZ-pi7JS-DT0pgsO>
>>
>> *From: *Karan Jain via Mesa-users <mesa-users at lists.mesastar.org>
>> *Sent: *Monday, February 1, 2021 12:14 PM
>> *To: *mesa-users at lists.mesastar.org
>> *Subject: *[Mesa-users] Science Fair
>>
>> Hello MESA users,
>>
>> I am having a bit of trouble with my science fair project. I am not too
>> sure exactly what I should look for. I registered for the physics division
>> of my science fair competition as there was no astrophysics or astronomy
>> category. I am using MESA to evolve a star until the end of AGB. I have all
>> the data, which are stars with a variable initial metallicity and initial
>> mass of 2 solar masses, and I have successfully converted it all to NumPy
>> arrays in python. I do not know where to go from here as my project is
>> based around metalicity but I need to relate it to a physics concept. I was
>> considering using machine learning and k-means clustering to see if I could
>> find any patterns but I realized that would not help me too much. I was
>> wondering if you have any advice as to how I should use the data that I
>> have to relate the effects of a variable metallicity to a concept in
>> physics and how I could use python to display that relationship. Attached
>> is an inlist_defaults file that I am using for one model.
>>
>> Thank You
>> Karan Jain
>>
>> _______________________________________________
>> mesa-users at lists.mesastar.org
>>
>> https://www.google.com/url?q=https://lists.mesastar.org/mailman/listinfo/mesa-users&source=gmail-imap&ust=1612807079000000&usg=AOvVaw00kST1O0NKdN5ckNWOGT9l
>> <https://www.google.com/url?q=https://www.google.com/url?q%3Dhttps://lists.mesastar.org/mailman/listinfo/mesa-users%26source%3Dgmail-imap%26ust%3D1612807079000000%26usg%3DAOvVaw00kST1O0NKdN5ckNWOGT9l&source=gmail-imap&ust=1612838612000000&usg=AOvVaw1dlbGITvrK1nP-obuHlRFP>
>>
>>
>>
>
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