Frequency analysis of heat-engine pulsators and solar-like oscillators
We will run this project with two groups in parallel, one supervised by Don Kurtz and one by Hans Kjeldsen
Pulsation frequencies are fundamental for asteroseismic inference. For this project you will be given time series data from the Kepler Mission for two mystery stars.
Using a Fourier transform plus least squares fitting package with GUI, Period04, that is freely available for all platforms, you will attempt to determine the frequency behaviour of your mystery star. The patterns of the frequencies in each project star have led to significant new astrophysical understanding. At the end of your project you will be able to compare what you have discovered to what a team of professionals discovered from the same data.
What will you conclude?
“Ha! I made a discovery the professional team missed!”
“Hey, I could have done all that!”
“Well, I got most of it.”
“Hmm, Ok, I missed a lot; that was an interesting lesson.”
“Wow, this stuff is a lot more complicated than I thought it would be.”
You will be given some theoretical foundation for Fourier analysis. Emphasis in the short training you will be given will be on methods and pitfalls in frequency analysis. During your project you will be given lifelines out of the pits you do fall into, and guidance about finding much that will not be easy to see at first. You will master the use of Period04, hence have in your toolkit a Fourier analysis programme for any time series data. If you choose this project, please download and install Period04 to your own computer at your earliest convenience; also download the instruction manual. Neither of these take long.
You will be provided with "mystery star" data on the first day of the school (data from Don, and data from Hans). For now, if you would like to play with Period04 and get a feel for its capabilities, in the attachment below is a short public data set for a Kepler star, KIC3429637, from Quarter 6. See what you can deduce from it. The data format is BJD - 2400000.0, Kepler magnitude (normalised to zero in the mean).
Data for Hans's Project:
Data for Hans's project are attached below. You are provided with Kepler data on Hans's "mystery star" from Quarter 2 (2.1, 2.2 and 2.3). There are two types of file for each, a raw file and a "corrected" file.
- hansmystery.zip: Data on Hans's "mystery star" (ZIP file, contains 6 ASCII files)