Analysis of Metallicity of Near-Sun Stars

        by Drew T. Johnson

        supervisor:  Bharat Ratra, Distinguished Professor of Physics

Kansas State University Physics Department  REU Program

 This program is funded by the National Science Foundation through grant number PHYS-1461251.  Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Below, I describe the Project Overview, my Research Description, my Research Progress, and will eventually post my Final Presentation and Final Report.  I post my homework assignments from our weekly REU scientific Ethics class, taught by Prof. Bruce Glymour , and my reaction to Prof. Larry Weaver's Lectures.   Scroll all the way down to learn more About Me.  Finally, I've included some Useful Links.  Hereís a page of my photos.  See my new bookmark. 

Project Overview:  Metallicity is a measure of the ratio of metal to hydrogen in a star relative to the Sun (a better description is linked below).  My research took data from a catalog of 3400+ stars and their metallicities for a range of different elements.

Research Description:  My research involved taking a large amount of data from the Hypatia catalog, which lists the metallicities of 3400+ stars, and fitting it to well-known distribution functions.Many cosmological measures (and many measures in physics in general) tend to follow some well-known distribution function, the purpose of this project was to attempt to fit metallicity measurements to a distribution function.The distributions we looked at in this project were Gaussian, Cauchy (or Lorentzian), Double Exponential (or Laplace), and Studentís t.The Hypatia catalog lists measurements of metallicity for many different metals, due to time constraints we only looked at Iron, Titanium, Silicon and Oxygen.My results and final presentation can be viewed in the Final Presentation section below

Final Presentation:  Click here to download my presentation in powerpoint and pdf formats. (still working on it)

Final Report: Not done yet... I just started.

Lectures:  Summary of interesting points.

First 5 weeks, we learned ??? I really  liked the discussion of ???, but struggled to understand ??

Ethics Class:

About Me:  I attend college at Kansas State University.

Useful Links: 

I have found the following links particularly informative or useful:


American Physical Society Statements on Ethics

American Institute of Physics

My Research group's home page