White Dwarfs

Dr. Williams studies white dwarfs, the slowly fading embers of stars that have exhausted their nuclear fuel. His research involves optical and ultraviolet observations of white dwarf stars. This research is currently funded by a Research Corporation Cottrell College Science Grant. Over the past five years, Dr. Williams has mentored seven REU students. Two of these students' work has already been published in leading astrophysical research journals, and two more papers involving other REU students are underway.

Student Opportunities

Students, in conjunction with Dr. Williams, will select one of the following projects that suits their interest and abilities:

Looking for star spots on white dwarfs

Some white dwarfs have strong magnetic fields that could generate star spots (similar to sunspots) on their surfaces. White dwarfs can rotate, and as spots come into view and go out of view, the white dwarfs vary in brightness. We will be looking for evidence of star spots and rotation in a selection of peculiar white dwarfs. If we find spots, we will measure the rotation period of these white dwarfs with the long term goal of determining how quickly these stars' rotation slows as the star's magnetic field interacts with interstellar magnetic fields.

Characterization of suspected cataclysmic variables

Cataclysmic variables are a type of binary star where the white dwarf remnant of a now-deceased star is able to accrete material from a close companion star. Ongoing searches for supernovae and other variable stars continually discover many cataclysmic variables, but most of these are not studied in any further detail. We will select some of these newly discovered objects for follow-up observations and determine how their light output changes with time. This will allow us to classify each cataclysmic variable and determine if any systems need further observations.

Timing of exoplanet transits

From our viewpoint on the Earth, a small fraction of planets around other stars will pass in front of their parent star each orbit. The planet blocks a tiny amount of the star's light, causing the star to dim slightly; this is called a transit. If there is a second planet in the planetary system, its gravity can change the exact times of the first planet's transit. By studying the times of transits, astronomers can potentially detect planets that we otherwise would not know about. We will select a small sample of exoplanets that are observable over the program and look for evidence of transit timing variations with a goal of determining the mass and orbit of other planets in an exoplanetary system

What You Will Do

Read and Understand Scientific Literature

Students will read journal articles from astronomical literature to understand the science behind each project, the analysis techniques we will use, and the goals of their projects.

Collect High-Quality Telescope Data

Students will learn how to take high-quality data with telescopes, including the SARA telescopes and the A&M–Commerce telescopes.

Perform Data Reduction

Students will learn the basics of data reduction—how raw images and calibration frames are transformed into scientifically useful information.

Produce and Model Light Curves

Using both newly collected and previously acquired data, each student will produce a light curve for their assigned object.
We will then model these light curves to determine key physical properties of each target.

Write and Submit a Research Paper

Students will write a journal-quality paper based on their findings.
These papers will be submitted to an appropriate publication venue, depending on project results.

Use Research Software Across Operating Systems

Over the course of the project, students will learn to use multiple pieces of software installed on computers with differing operating systems to analyze astronomical data.

Learn Statistics and Research Ethics

Students will gain foundational knowledge in statistics and research ethics relevant to astronomy research.

Communicate Scientific Information

All students will practice conveying scientific information in both verbal and written formats.