Dr. Nathan Lee

deleenm@nku.edu

Research Statement of Dr. De Lee

The focus of my research is the variable sky. By tracking how stars change over the course of hours, days, weeks, and even years, we can learn about a wide variety of topics including variable stars and stellar companions. In the variable star programs, I work primarily with RR Lyrae stars, which are ancient stars the pulsate over the course of half a day. These beacons can be used to map out the history and structure of our home galaxy, the Milky Way. We are currently using an 11-inch telescope on the NKU campus to generate multi-color light curves of these stars. In the stellar companion programs, I am particularly interested in exoplanets (planets outside our solar system) and brown dwarfs (failed stars). Much of my work is done using large astronomical surveys. I am currently working with the SDSS-IV APOGEE-2 galactic survey, with the TESS transiting exoplanet satellite, and in preparation for the Large Synoptic Survey Telescope (LSST).  Below are two projects I am currently working on.

Searching for Stellar Companions in APOGEE-2
This work focuses on measuring how stars wobble based on the presence of a companion. These companions can be other stars, brown dwarfs, or exoplanets. The goal of this research is understand how these different types of systems form. In particular, brown dwarfs are interesting because they have masses in between those of stars and planets. By understanding in what environments brown dwarfs form in we can answer basic questions about how planet formation works in general. The question this work tries to answer is: "How do planets and brown dwarfs form around new stars?"

Building the TESS Input Catalog
The TESS satellite is scheduled to launch in December 2017. I am part of a group working choosing what stars the TESS satellite will obtain data on. The TESS satellite's mission is to survey bright (and usually nearby) stars for exoplanets. Since only a limited number of stars can be observed, we have to create a giant catalog of all the stars in the sky down to quite faint levels. We also work on techniques to separate dwarf from giant stars, since it is difficult to detect planets around giant stars. This ultimate goal of this project is to help answer the question: "How many and what types of planets are in the solar neighborhood?"