Faculty and Staff
The BYU astronomy research group is part of the Department of Physics and Astronomy in the College of Physical and Mathematical Sciences. The group currently consists of 6 full-time faculty members, a planetarium director, a part-time instructor, 4 graduate students, 108 declared undergraduate majors, and 16 astronomy minors. We currently operate 10 optical telescopes that range from 6" to 0.91-m, at three different locations in Utah. We also joined the Astrophysical Research Consortium (ARC) in January 2021 to provide guaranteed access to a 3.5-m telescope.
Members of the group also make use of wide variety of external telescopes such as the Hubble Space Telescope and the ALMA array. Please follow the links below to explore the activities of the research group, opportunities for graduate studies, and use of the our telescopes.
We note that we have an additional faculty member who will hopefully join the faculty in the future, Alexander Mosenkov. However, due to world events we are not sure when he will be able to formally join the department. We also note that there are other faculty in the department who work on astronomy/astrophysics problems. On the general department page please find David Neilsen, Eric Hirschmann, David Allred, and Steve Turley. Jani Radebaugh of the geology department works in the area of planetary science.
- Building an Atlas of Molecular Gas Kinematics From the ALMA Archive
Archival data from the Atacama Large Millimeter/submillimeter Array (ALMA) reveal molecular gas in many early-type galaxies (ETGs, including elliptical and S0 types). In many cases, the observations trace regular rotation about the galaxy center. However, relatively few of these data sets have been published, and there is little consistency between the published data products. We are uniformly measuring gas properties in a large sample of ETGs with ALMA carbon monoxide (CO) observations, which will then be compiled into an atlas of molecular gas kinematics in luminous galaxies. In addition to measuring and analyzing kinematic properties, this atlas will also help identify candidates for higher angular resolution ALMA imaging to measure the mass of the central supermassive black hole mass.
- Dust Attenuation in Circumnuclear Disks
Roughly 10% of all elliptical and S0-type galaxies contain morphologically round dusty disks that obscure stellar light behind these disks. These molecular gas-rich disks are prime candidates for precision mass measurement of the supermassive black hole (BH) at the disk centers. Unfortunately, the high dust column densities preclude any confident determination of the host galaxy mass profile simply by modeling the observed stellar light distribution in optical (and often even near-IR) images. Using a large sample of multi-wavelength data obtained with the Hubble Space Telescope (HST), we are modeling the dust attenuation of these circumnuclear disks to recover a range of plausible dust-corrected stellar mass models. These will be used to more confidently constrain BH masses in about 30 elliptical and S0 galaxies.
- Dust Properties From ALMA Observations
Cold dust found at the centers of many nearby galaxies emits thermal radiation. With typical temperatures of 10-30 K, the dust black body spectrum peaks in the far-IR range. In many cases, the Rayleigh-Jeans tail of the dust thermal emission is detectable at mm-wavelengths with the Atacama Large Millimeter/submillimeter Array (ALMA). Together with continuum measurements from the radio to the mid-IR, data points at ALMA wavelengths are important when measuring dust mass and temperature. We are measuring ALMA continuum flux densities (or upper limits) and building spectral energy distributions (SEDs) to separate out non-thermal contributions and model the SEDs as using a modified black body function.
- Supermassive Black Hole Mass Measurement
The improved sensitivity and larger baselines of the Atacama Large Millimeter/submillimeter Array (ALMA) now enable imaging of molecular gas deep within the centers of numerous nearby galaxies. In a small percentage of luminous elliptical galaxies, ALMA observations trace the motion of molecules like carbon monoxide (CO) well within the supermassive black hole's (BHs) sphere of influence, wherein the BH dominates the overall gravitational potential. Using detailed gas-dynamical models, we are able to measure the BH mass and determine its overall error budget.
- Astronomy Education
I'm currently working on a number of projects to do with astronomy education.
1) We are also examining our constellation quiz to provide a baseline level and determine which constellations and bright stars students know when they start the class. What to test difference between Digistar and Zeiss projectors.
2) Development of a core set of test questions for descriptive astronomy class.
3) Will likely do a modified project on teaching moon phases to improve on a past MS project.
4) Work on bring robotic telescopes into the Phscs 127 class.
- Impact of Cadence on Variable Classifcation by Machine Learning
This is a project to examine how little data is needed to determine an accurate period in the pulsations of a short period variable star. There are many large survey programs running, or soon to be running, that find new variable stars. Through machine learning they try to classify these objects. However, for short period variables the classifications and periods determined, are found to often be wrong.
We are also examining the impact of space velocity on the measurements, phase jumps in the pulsation curve, and measurement errors.
We do observational work to follow-up on these new variables and modeling work to show the limits.
This is a program that is currently very active and where students are needed.
- Period Changes in Medium Amplitude delta Scuti Variables
In general, researchers consider there to be two groups of delta Scuti variables; the High Amplitude delta Scuti (HADS) and the Low Amplitude delta Scuti (LADS). However, the in between realm is interesting. The Medium Amplitide delta Scuti stars seems to show a range of changes in both amplitude and period. This makes them a very interesting group to monitor. Often we participate with astronomers from around the world in taking data for these projects.
We are now adding some computer modeling to try to better understand these changes.
- Spectrophotometic Comparison of H-alpha and H-beta IndexTraditionally the H-beta index has been used as a reddening free index to measure the surface temperature of stars. Prof. Joner in the department has developed a new H-alpha index that has great promise. We are working together to spectrophotometrically compare the two systems.
- Spectroscopic Survey of Northern Sky delta Scuti VariablesTo understand the nature of the delta Scuti variables in the instability strip one needs as much information as possible about the stars. However, an examination of the catalog of delta Scuti variables shows a lack of basic information on many of the group. Of the 247 delta Scuti stars visible in the northern hemisphere we currently have spectra of 242 of them. These need to be reduced to provide estimates of some basic stellar properties like [Fe/H], radial velocity, rotational velocity, and perhaps information on any binary companions.
- Variable Star Search in Open ClustersWe are currently searching for new low amplitude variable stars in a large sample of open clusters. The clusters cover a wide range of ages and will provide a evolutionary test of how the variable stars change with age. We are also looking for very small eclipses that might be the sign of a planet.
- Photometric Reverberation MappingTraditional reverberation mapping to estimate AGN black hole masses uses a combination of photometry and spectroscopy to determine the time lag between variations that occur at the accretion disk and then later in the broad line region. With such techniques, there is a need for a large amount of moderate to large telescope time in order to secure the spectroscopic data with an observing cadence suitable for a determination of the time lag. Photometric reverberation mapping uses a single epoch spectroscopic determination of the broad line region velocity and a time lag determination based on photometric observations that include predominantly continuum features or broad line components that can be seen to vary at a later time. This technique is still being tested but hold promise for the determination of black hole masses in the age of several large scale surveys.
- Testing the standard model of active galactic nuclei through automated multi-color broadband CCD imagingRemote Observatory for Variable Object Research is a 16" RC Optical telescope on a Paramount pier sited near Delta Utah. Operational since 2008, it is used to remotely monitor active galactic nuclei (AGNs) which includes blazars, quasars, Seyfert nuclei and Low Ionization Nuclear Emission Regions, or LINERS. The standard model of AGNs assumes each is a supermassive black hole surrounded by an accretion disk. The disk is fed by a more extensive lower-density region surrounding it. The disk brightens and dims as gas falls upon it and as dusty clouds orbiting around it obscure it from our view. Optical variability measures these effects providing data that can be used to model the specific nature of different AGNs.
- Orbits in the Outer Solar SystemBeyond the orbit of Neptune lies a population of icy bodies whose orbits can reveal unique information about how our solar system formed. This region of the solar system is called the Kuiper Belt and these small icy bodies are called Kuiper Belt Objects (KBOs or sometimes Trans-Neptunian Objects or TNOs), though some are large enough to also qualify as "dwarf planets" like Pluto and Haumea. There are multiple projects available in my research group to study KBO satellites (e.g., Haumea's moons) and KBO orbits (e.g., the Haumea and other collisional families). There are a variety of projects available at a variety of levels. Please contact me for more information.
- Studying the Architectures of Exoplanetary Systems
Like our Sun, other stars are known to host planetary systems. As we continued to discover many more exoplanetary systems, we learn about how these systems are put together. The "architecture" of these systems (are small planets on the inside or outside? how close are the planets to each other? etc.) gives us invaluable clues to the formation of planetary systems. I used state-of-the-art statistical and computational techniques to discovery new exoplanetary systems, study existing systems, and remove the biases on their properties from our limited observational methods. I have many projects at different levels and durations available for students. Please contact me for more information.
- Brown Dwarf Binary Systems - modeling
Looking at peculiarities in the spectra of known binary brown dwarfs. Trying to understand the large number of L/T transition binaries, and why the spectra of these objects change so quickly over a constant temperature range. We want to determine binary statistics with spectral type, and how many of the L/T objects are truly single objects. We want to understand which spectral features vary the most between a single brown dwarf and an unresolved binary system, so we can use these spectral features as a way to identify binaries from existing spectra. Eventually we will use high resolution photometry and psf fitting to identify marginally resolved and unresolved binaries.
- Education - Learn Astropy and create training videos
I would love to have a student work through several tutorials I have that teach astropy, learn it very well, and then create zoom videos and jupyter notebooks that future students can use to learn how to use astropy to do photometry and spectroscopy. They could even extend this beyond to creating notebooks and videos to reduce TESS data (or any data from the roof) and in the future notebooks that can reduce APO data.
- Spectrophotometry of brown dwarfs observed with ARC 3.5 meter
Use IDL to reduce spectra of brown dwarfs taken with the ARC 3.5 meter telescope.
- Transiting ExoplanetsTake data with the 16" telescope on the roof of the Eyring Science Center of stars that may have transiting planets. Reduce this data using IRAF and AstroimageJ software. Characterize the radius of the planet (if we see a transit) by fitting the transit light curve. Return results to the team so that we can either obtain further observations of a possible planet candidate or expire the target as spurious or an eclipsing binary star system.
- Variability in Brown DwarfsReduce Spitzer observations of 3 brown dwarfs taken sequentially in time to look for evidence of variability. If variability exists, the amplitude is very low. The evidence of variability would suggest that cloud features or holes in the clouds are not homogeneously distributed across the surface.