Research Page
More information about the work I am doing.
NSF Funded Work
I was awarded a two year grant starting in January 2022 under the Launching Early-Career Academic Pathways in the Mathematical and Physical Sciences (LEAPS-MPS) program of the National Science Foundation (Award #2137787) to study a class of radially pulsating stars known as RR Lyrae type variables. We are using Transiting Exoplanet Survey Satellite (TESS) data to identify transient changes in the lightcurves of these variable stars, and then perform follow-up observations at McDonald Observatory while TESS is re-observing the stars to get a more complete picture of what could be causing the changes in the pulsations.
A major component of this grant is focused on increasing the participation of historically underrepresented groups in astronomy. By training undergraduate students to analyze data from large surveys (such as TESS), in addition to providing them with the experience of obtaining observations using world-class telescopes and instruments (at McDonald Observatory), the hope is that this will inspire these students to continue pursuing astronomy and give them the tools and experiences required to be successful.
SDSS FAST Program
Starting in the summer of 2021 I was awarded a grant as part of the Sloan Digital Sky Survey Faculty and Student Team Initiative (SDSS FAST). This program is also focused on increasing participation from historically underrepresented groups.
For the 21-22 academic year, we combined data from SDSS and TESS to develop a calibration to find spectroscopically determined properties of RR Lyrae stars using photometric lightcurves. This will allow us to obtain these properties for stars not observed by SDSS to extend to farther distances and different parts of the Milky Way. This work was presented at the national American Astronomical Society (AAS) meeting in June 2022 in Pasadena, CA.
For the 22-23 academic year we are planning to compare individual elemental abundances of three distinct populations of stars (RR Lyrae, RGB, and AGB) found in the globular cluster NGC 3201. This cluster is believed to be inhomogeneous in composition, and an analysis of stars in different evolutionary stages would help confirm this. It will also allow us to create criteria for confirming members of this cluster at larger radii and potentially stripped out in tidal streams.
The 23-24 academic year will be an extension of the 22-23 year's work where we see if the results we got for NGC 3201 are normal for other globular clusters, or if that cluster is different in some way.
ASU FREP Program
I have been awarded three different year-long grants while at Angelo State University through the Faculty Research Enhancement Program.
- For the 18-19 academic year, we did a study of shockwaves in RR Lyrae stars using high-resolution spectroscopy from McDonald Observatory.
- For the 20-21 academic year, I developed a software package named ATARRI (ascl:2105.003) written in python for downloading and analyzing TESS data of RR Lyrae stars. We also published an article in The Astrophysical Journal Letters that was the first to report a new type of behavior in a certain type of RR Lyrae variable star ( Carrell et al. 2021, ApJL, 916, L12). This work was a precursor to the NSF grant-funded work.
- For the 23-24 academic year, we are going to setup along the path of the total solar eclipse on April 8, 2024 and take images of stars near the Sun during the eclipse. By measuring the very small changes in the positions of stars during the eclipse as their light passes near the Sun, we will be able to verify an important aspect of General Relativity. This modern version of the Eddington Experiment will also hopefully allow us to definitively determine the functional form of the stellar deflections.