SPS Zone 5 Home Page: Student Abstracts I

Simulating Exoplanets and Radial Velocity Curves
Mark Montazer (High Point University)

The most prolific method for detecting exoplanets is the radial velocity method. As discoveries are published, they are generally accompanied by data, a set of orbital parameters, and a statistical justification of the conclusions. Using both Keplerian mechanics and Newtonian mechanics, this project used Easy Java Simulations (EJS) to recreate numerous published planetary systems with a nearly identical level of statistical accuracy.


Investigating the Orbits of Asteroids with the HORIZONS Database
Matthew Marcum, Anthony Crider (Elon University)

The HORIZONS database was designed by NASA to allow users to calculate the locations of Solar System objects. We used it to generate where and when asteroids orbited in space. The PROMPT telescope array was then used to take pictures of specific asteroids as they made close approaches to Earth. Using computer software, positional coordinates were assigned to the asteroids in the pictures. These positions were then compared with the original data from HORIZONS to judge the accuracy of the telescopes. A computer program was then designed that modeled HORIZONS. The program was tested against HORIZONS for the asteroid Apophis.


Eclipse Light Curves of U Geminorum
Chelsea M. Grandy, Raya I. Cooper, and Donald F. Collins (Warren Wilson College)

U Geminorum is a dwarf nova type cataclysmic variable star that consists of a white dwarf star and a cool main sequence star. The dominant source of radiation is the hot region between these stars in an accretion disk. The high orbital inclination of the system produces a partial eclipse every cycle (approx 4.3 hr). With time series observations, obtained with a CCD camera and 20 cm telescope, we observed details in the structure and morphology of the U Geminorum system. We also observed significant daily changes in the light curves.


Emission and Reflection Nebulae
Raya I. Cooper, Chelsea M. Grandy, and Donald F. Collins (Warren Wilson College)

We photographed emission and reflection nebulae though broad-spectrum visible light filters and through a narrow band hydrogen alpha filter using a telescope and CCD camera. For each filter we measured nebula brightness relative to a nearby star's brightness by means of image profiling. Because much of the emission consists of the hydrogen alpha line induced by UV from a nearby star, we observed that emission nebulae appear bright using a hydrogen alpha filter. Broad-spectrum starlight is strongly attenuated through the narrow band filter. Reflection nebulae merely reflect the starlight from nearby stars and do not emit in hydrogen alpha.


Fabrication of High Performance Organic Thin-Film Transistors by Spray Deposition
Natalia Azarova (Wake Forest University), Jack Owen (Wake Forest University), Marsha A. Grimminger (University of Kentucky), Eric Chapman (Wake Forest University), John E. Anthony (University of Kentucky), and Oana D. Jurchescu (Wake Forest University)

We report on spray deposition, an innovative coating technique for organic thin film transistors fabrication. Factors affecting spray deposition include pressure, gas-to-solution ratio, spray distance, solution concentration and spray time. Our devices show good homogeneity, with the best mobilities of 0.2 cm2/Vs, and on/off ratios of 10^7. This performance is comparable to that of our best spin-coated devices, while offering additional advantages such as direct scalability with large area applications. Our results demonstrate the viability of the spray approach, and open new routes to low-cost fabrication of organic electronic devices.